TABLE 2.

Functions and mutant phenotypes of T4 gene products

GeneaFunction of gene productbSize (kDa)bMutant phenotypeRestrictive host or conditioncReference(s)
rIIAMembrane-associated protein; affect host membrane ATPase82.9Rapid lysis; suppress T4 30 and some 32 mutationsAuxiliary; rex+ λ lysogens; P2-like HK239 lysogen; tabR2-4, 56, 59, 95, 96, 106, 121, 159, 181, 184, 191, 198, 216, 224, 263, 292, 293, 365, 375, 441, 430, 431, 451, 504, 582, 768, 769, 774, 793, 810, 811, 834, 851, 874, 940, 1007, 1021, 1059, 1114b, 1159,
60DNA topoisomerase subunit18.6DNA delay; rc = acriflavine resistanceEssential; 25°C or below447, 450, 451, 452, 653, 654, 681, 801, 968, 1037
mobAPseudogene of Mob site-specific DNA endonuclease4.2NonessentialE. Thomas, F. Zucker, and E. Kutter, unpublished data
39DNA topoisomerase subunit; DNA-dependent ATPase; membrane-associated protein58.0DNA delay; rc = acriflavine resistanceEssential; 25°C or below; synthetic lethal with T4 49 and 17 mutations, or when host topoisomerase IV is poisoned with novobiocin264, 297, 295, 296, 432, 447, 448, 449, 451, 452, 454, 571, 589, 653, 654, 708, 789, 768, 769, 801, 834, 853, 1006, 1037, 1047, 1059, 1216, 1236
goF = comC-α = go9HAffects mRNA metabolism16.7Allows T4 growth in rho (nusD) hostsAuxiliary144, 431, 474, 879, 925, 956, 1028, 1044, 1045, 1062, 1154, 1241
cef = mb = M1 = motCProcessing of T4 tRNAs8.5Auxiliary; CT439; roc hosts431, 869, 870, 878, 937, 956
pseF = plaCTr5x?5′ phosphataseAuxiliary956
motB18.2Affects middle transcriptionAuxiliary956
dexAExonuclease A26.0Auxiliary; restricted on optA hosts308, 355, 431, 604, 737, 780, 956, 1152
dda = sudDNA helicase; DNA-dependent ATPase49.9Suppress certain T4 32 mutationsAuxiliary; synthetic lethal with T4 59 mutations45, 309, 369, 431, 481, 546, 547, 587, 588, 649, 680, 769, 780, 783, 956, 970; P. Gauss, personal communication
srd = dda.2Postulated decoy of host σ70 or σS29.1Auxiliary780
modAAdenylribosylating enzyme23.4α subunits of host RNA polymerase are incompletely modifiedAuxiliary324, 431, 435, 780, 1011, 1077
modBAdenylribosylating enzyme24.2Auxiliary780, 1077
srh = modA.5Postulated decoy of host σ328.1Delays early T4 gene expression at high temperaturesAuxiliary780
mrhAffects phosphorylation of host σ3218.5Allows T4 growth in a σ32 hostAuxiliary290, 780
socSmall outer capsid protein9.1Unstable T4 capsidsAuxiliary77, 89, 167, 431, 461, 462, 466, 675, 780, 916, 918
segF = 69Intron-like endonuclease. A probable fusion protein, generated from 56 and 69 by hopping of ribosomes across a pseudoknot, is larger26.2Nonessential51, 305, 677, 769, 780, 790, 783
56dCTPase; dUTPase; dCDPase; dUDPase20.4Little DNA synthesis; unstable DNAEssential305, 347, 602, 605, 696, 769, 781, 783, 839, 1162
oriADNA replication origin; cis-acting sequences in 56, 69, and soc; primer transcript same as transcript for these genesNo DNA synthesis from oriAAuxiliary160, 674, 678, 691, 791, 1215
damDNA adenine methylase30.4No DNA adenine methylationAuxiliary112, 139, 395, 676, 677, 683, 742, 743, 921, 960, 961, 1072
61 = 58Primase; requires interaction with gp41 helicase for priming at unique sequence39.8DNA delayAuxiliary; 25°C or below; synthetic lethal with T4 49 or 17 mutations17, 47, 60, 123, 154, 380, 415, 416, 421, 422, 652, 653, 667, 761, 768, 769, 783, 788, 801, 829, 826, 831, 970, 996, 997, 998, 1216
sp = 61.3 = rIVPeriplasmic protein11.0Rapid lysis; suppresses e lysozyme mutationsAuxiliary2, 261, 492, 585, 851, 971, 1208
dmd = 61.5Discriminator of mRNA degradation7.0Excessive mRNA degradationNonessential; suppressed by motA mutations491, 493, 971, 1102/PICK>
41Replicative and recombination DNA helicase; GTPase; ATPase; dGTPase; dATPase53.6DNA arrest; little DNA displacement synthesisEssential17, 54, 60, 154, 155, 184, 197, 227, 228, 264, 309, 424, 415, 416, 421, 451, 478, 479, 554, 593, 653, 652, 651, 761, 768, 769, 826, 831, 838, 930, 931, 950, 970, 1029, 1064, 1122, 1220
40Membrane-associated protein initiator of head vertex13.3PolyheadsAuxiliary; high temperatures89, 115, 116, 301, 416, 443, 500, 608, 693, 729
uvsX = fdsARecA-like recombination protein; DNA-ATPase44.0UV- and X-ray sensitive; recombination deficient; suppress 49 mutationsAuxiliary26, 80, 82, 165, 182, 213, 254, 282, 283, 281, 301, 351, 384, 386, 392, 416, 423, 549, 572, 589, 686, 723, 739, 762, 768, 769, 938, 949, 950, 970, 1047, 1088, 1138, 1222-1225
segASite-specific intron-like DNA endonuclease25.3Nonessential986, 988
β-gtβ-Glucosyltransferase40.7No β-glucosylation of HMC DNAAuxiliary; Shigella139, 316, 451, 615a, 757, 924, 1075, 1084, 1134
42dCMP hydroxymethylase28.5Little or no DNA synthesisEssential60, 68, 124, 184, 264, 320, 348, 383, 451, 476, 475, 477, 598, 611, 612, 695, 698, 834, 1027, 1076, 1114a, 1165, 1192
immInner membrane protein9.3No immunity to superinfectionAuxiliary2, 3, 4, 166, 188, 665, 666, 836, 1113, 1232
43DNA polymerase; 3′-to-5′ exonuclease103.6No DNA synthesis; mutator or antimutator activities of conditional lethals under semipermissive conditionsEssential; nonessential dsd mutants do not grow in optA hosts1, 17, 20, 21, 23, 24, 36, 43, 53, 54, 57, 58, 60, 68, 94, 130, 212a, 229, 230, 231, 237, 264, 259, 289, 298, 334, 343, 394, 393, 451, 488, 495, 506, 507, 527, 529, 555, 581, 617, 645, 646, 653, 689, 768, 769, 826, 827, 828, 831, 834, 856, 857, 903, 904, 905, 906, 907, 908, 909, 910, 911, 912, 913, 914, 970, 978, 983, 1029, 1030, 1033, 1046, 1088, 1128, 1142, 1143, 1147, 1150, 1165, 1207
regATranslational repressor of several early genes14.6Extended synthesis of several early proteinsAuxiliary; restricted in E. coli rpoB5081 at 42°C9, 10, 19, 131, 320, 338, 484, 485, 503, 505, 637, 735-738, 835, 860, 951, 952, 953, 975, 1095, 1167, 1182
62Clamp-loader subunit21.4No DNA synthesisEssential17, 20, 57, 60, 264, 310, 311, 312, 320, 451, 469, 470, 486, 487, 488, 616, 619, 653, 679, 826, 831, 834, 865, 864, 901, 902, 1089, 1217, 1227
44Clamp-loader subunit35.8No DNA synthesisEssential20, 57, 310, 311, 312, 320, 469, 470, 486, 487, 488, 616, 618, 619, 679, 826, 831, 864, 865, 901, 902, 970, 1032, 1089, 1217, 1227
45Processivity enhancing sliding clamp of DNA polymerase; and mobile enhancer of late promoters24.9No DNA synthesis; no late transcriptionEssential17, 20, 22, 264, 299, 310, 311, 312, 320, 334, 404, 405, 451, 469, 552, 552a, 616, 617, 619, 618, 653, 673, 679, 747, 786, 826, 831, 834, 865, 901, 902, 951, 952, 953, 970, 983, 1031, 1079, 1080, 1081, 1082, 1091, 1092, 1186, 1217, 1227
rpbARNAP-binding protein14.7Auxiliary444, 552, 786, 1171, 1172, 1174
46Recombination protein and nuclease subunit63.6Recombination deficient; DNA arrest; no host DNA degradationEssential in B strains; mutants are “leaky” in some K strains60, 68, 93, 111, 184, 195, 264, 345, 380, 403, 451, 605, 627, 668, 731, 740, 744, 768, 769, 775, 784, 1036, 1047, 1138, 1163, 1164
47Recombination protein and nuclease subunit39.2Recombination deficient; DNA arrest; no host DNA degradationEssential in B strains; mutants are “leaky” in some K strains93, 345, 403, 605, 731, 744, 768, 769, 1036, 1164
α-gtα-Glucosyltransferase46.7No α-glucosylation of HMCAuxiliary140, 316, 345, 437, 924, 1072, 1084, 1191
mobBPutative site-specific intron-like DNA endonuclease30.4Nonessential48, 1072
55σ factor recognizing late T4 promoters21.5No late transcriptionEssential97, 98, 109, 310, 313, 311, 345, 404, 552, 635, 834, 895, 1038, 1082, 1171, 1173, 1174, 1186
nrdH = 55.7Anaerobic nucleotide reductase subunit11.7Auxiliary257, 368, 1085
nrdG = 55.9Anaerobic nucleotide reductase subunit18.2Auxiliary660, 1228
mobC = 55.10Putative intron-like DNA endonuclease24.0Auxiliary1072
nrdD = sunYAnaerobic ribonucleotide reductase subunit; RNA contains a self-splicing intron68.0Anaerobic growth39, 342, 882, 1053, 1086, 1203, 1229, 1237; M. Ohman-Heden, personal communication
I-TevIIEndonuclease for nrdD-intron homing30.4Nonessential52, 178, 251, 342, 661, 662, 882, 993, 991, 1085
49Recombination endonuclease VII18.1No resolution of recombination junctions; incomplete packaging of DNA; reduced heteroduplex repair, reduced DNA synthesisEssential39, 70, 79, 81, 82, 172, 213, 249, 250, 278, 300, 285, 330, 331, 332, 333, 350, 522, 523, 524, 525, 526, 541, 559, 669, 670, 740, 768, 769, 783, 788, 792, 793, 817, 883, 1025, 1030, 1029, 1047, 1083, 1085, 1226; G. Mosig and D. Powell, Abstr. Annu. Meet. ASM, p. 209, 1985
49Internal translation initiation product11.939, 784, 788
pinInhibitor of host Lon protease18.8Degradation of amber peptidesAuxiliary1005, 1012, 1085
nrdCThioredoxin, glutaredoxin10.1Auxiliary64, 257, 341, 460, 632, 815, 816, 1066, 1085
mobDPutative site-specific DNA endonucleasee30.5Nonessential1072
rI = tk.-2Membrane protein11.1No lysis inhibitionAuxiliary3, 56, 224, 236, 851
tkThymidine kinase21.6Auxiliary156, 157, 348, 604, 696, 733, 1112; Thomas et al., unpublished
vsModifier of valyl-tRNA synthetase13.1Auxiliary688, 713, 842, 843, 1112
regBSite-specific RNase18.0Misregulation of early genes; specific mRNAs stabilizedAuxiliary156, 736, 942, 943, 955, 1106, 1112
denVEndonuclease V; N-glycosidase16.1UV sensitiveAuxiliary35, 219, 222, 223, 232, 304, 339, 575, 604, 620, 621, 622, 623, 656, 657, 685, 714, 715, 716, 718, 758, 806, 812, 813, 832, 862, 884, 885, 899, 969, 1110, 1111, 1112, 1117, 1120, 1151, 1212, 1213
ipIIInternal protein II11.1∗ 9.9Auxiliary84, 88, 89, 442, 595, 604, 1093, 1112
ipIIIInternal protein III21.7∗ 20.4Auxiliary84, 88, 89, 442, 434, 451, 595, 604, 802, 803, 804, 1093, 1112, 1114a
eSoluble lysozyme; endolysin18.7No cell lysisEssential, except when suppressed by sp and 5 mutations2, 3, 4, 50, 261, 268, 346, 500, 594, 604, 704, 720, 787, 850, 871, 872, 948, 1050, 1099, 1158, 1193
nudE = e.1Nudix hydrolase17.0Auxiliary1204
goF3Allow T4 growth in nusD rho hostsAuxiliary720, 1045
rnaC = species 1Stable RNANonessential110, 302, 707, 870, 962
rnaD = species 2Stable RNANonessential110, 302, 707, 870, 962
tRNAArgpsu4 opal suppressorAuxiliary; CT4395, 110, 284, 302, 328, 361, 366, 367, 501, 707, 710-712, 870, 962, 964, 1178, 1179, 1180
segBProbable site-specific intron-like DNA endonuclease26.2Nonessential110, 302, 604, 772, 988
tRNAIleAuxiliary; CT439302, 707, 962
tRNAThrAuxiliary; CT439302, 707, 962
tRNASerpsua; psub; psut; amber suppressorsAuxiliary; CT439302, 707, 962
tRNAProAuxiliary; CT439302, 707, 962
tRNAGlyAuxiliary; CT439302, 707, 962
tRNALeupsu3Auxiliary; CT439302, 707, 962
tRNAGlnpsu2; SBAuxiliary; CT439302, 707, 962
ip1Internal protein 110.2∗ 8.5Auxiliary; CT5966, 84, 87, 88, 89, 110, 442, 543, 595, 1093, 1112
57B17.3?110, 280, 409, 410, 922
57AChaperone of long and short tail fiber assembly8.7Defective tail fiber assemblyEssential; bypassed by certain host mutations110, 122, 186, 319, 391, 401, 409, 410, 699, 922
1dNMP kinase27.3No DNA synthesisEssential110, 184, 241, 264, 348, 543, 696, 834
3Head-proximal tip of tail tube19.7Unstable tailsEssential7, 186, 264, 535, 536, 543, 648, 1124
2 = 64Protein protecting DNA ends31.6Noninfectious particles with filled headsEssential, except in recBCD hosts28, 89, 186, 249, 250, 264, 543, 647, 1000, 1001, 1074, 1144
4 = 50 = 65Head completion protein17.6Noninfectious particles with filled heads but tails attached at wrong anglesEssential89, 249, 250, 264, 543, 787
53Base plate wedge component23.0Defective tailsEssential186, 249, 250, 530, 531, 532, 787, 1155, 1157
5Base plate lysozyme; hub component63.1∗ 44* 19Defective tailsEssential2, 186, 249, 264, 497, 500, 530, 531, 532, 787, 807, 1063, 1119, 1157
oriEDNA replication origin; cis-acting sequences in genes 4, 53, 5; primer transcript in opposite orientation of gene 5 transcriptsNo DNA synthesis from oriEAuxiliary378, 563, 641, 779, 1109, 1215; G. Lin and G. Mosig, unpublished data
repEBProtein required for initiation from oriE5.48No DNA replication from oriEAuxiliary; synthetic lethal with motA mutation1109
repEAProtein auxiliary for initiation from oriE6.13Anomalous DNA replication from oriEAuxiliary1109
segCSite-specific intron-like DNA endonuclease16.0Nonessential490, 641, 988, 989a; Lin and Mosig, unpublished
6Base plate wedge component74.4Defective tails; permit plating of fiberless phageEssential186, 193, 249, 253, 264, 537, 1119, 1157; R. Marsh, personal communication
7Base plate wedge component119.2Defective tails; permit plating of fiberless phageEssential186, 193, 249, 250, 253, 264, 537, 1119, 1156, 1157; Marsh, personal communication
8Base plate wedge component38.0Defective tailsEssential186, 250, 249, 253, 264, 537, 1119, 1156, 1157
9Base plate wedge component, tail fiber socket, trigger for tail sheath contraction31.0No attachment of tail fibersEssential186, 250, 264, 535, 537, 562, 876, 1114a, 1155, 1157
10Base plate wedge component, tail pin66.2Defective tailsEssential186, 249, 250, 264, 272, 537, 726, 867, 868, 876, 1119, 1155, 1156, 1157, 1239
11Base plate wedge component, tail pin, interface with short tail fibers, gp1223.7Defective tailsEssential186, 249, 250, 264, 535, 537, 633, 868, 867, 876, 1119, 1155, 1157, 1239
12Short tail fibers56.2Defective tailsEssential122, 186, 391, 521, 535, 537, 745, 972, 1114a, 1155, 1157
wacWhiskers, facilitate long tail fiber attachment51.9No whiskersAuxiliary186, 214, 745, 877, 1024, 1065, 1114a, 1188
13Head completion34.7Inactive, but filled headsEssential89, 249, 250, 264, 973, 1114a
14Head completion29.6Inactive, but filled headsEssential89, 250, 249, 264, 973, 1114a
15Proximal tail sheath stabilizer, connector to gp3 and/or gp1931.6Defective tailsEssential249, 250, 264, 272, 535, 537, 973, 1114a
16Terminase subunit, binds dsDNA18.4Empty headsNearly essential85, 86, 89, 90, 249, 250, 264, 286, 287, 642, 643, 644, 669, 802, 803, 873, 891, 1194
16Truncated C-terminal end
17Terminase subunit with nuclease and ATPase activity; binds single-stranded DNA, gp16 and gp2069.8Empty headsEssential75, 85, 86, 89, 90, 249, 250, 264, 286, 287, 288, 433, 586, 631, 642, 643, 669, 746, 769, 784, 785, 873, 891, 892, 893, 1194, 1195, 1196
17ATerminase subunits with nuclease and59.2?286, 287, 288, 333, 784
17BATPase activity; internal transcription and translation in frame; does not bind ssDNA57.1
17"Terminase subunit with nuclease and ATPase activity (transcript processing and internal initiation of translation in frame); does not bind ssDNA; several additional proteins most likely initiated from internal ribosome binding sites of the 17 transcripts46.8?286, 287, 288
18Tail sheath monomer71.3Defective tailsEssential29, 31, 186, 249, 250, 264, 272, 535, 537, 1096, 1119, 1157
19Tail tube monomer18.5Defective tailsEssential30, 186, 249, 250, 264, 272, 535, 536, 537, 1119, 1157, 1194
20Portal vertex protein of the head61.0PolyheadsEssential86, 89, 90, 238, 250, 264, 333, 608, 642, 643, 694, 990, 1114a
pip = 67Prohead core protein; precursor to internal peptides9.1∗ small peptidesDefective headsEssential89, 519, 1130, 1131
68Prohead core protein15.9Isometric headsEssential89, 516, 518, 520
21Prohead core protein and protease23.3∗ small peptidesNo or defective headsEssential89, 250, 264, 329, 414, 516, 517, 606, 608, 844, 845, 990, 1116
21Prohead core protein and protease (internal initiation of translation)20.8∗ small peptidesDefective heads414
22Prohead core protein; precursor to internal peptides29.9∗ small peptidesNo or faulty headsEssential89, 250, 264, 270, 518, 595, 608, 728, 805, 844, 845, 990, 1094, 1093, 1114a
23Precursor of major head subunit56.0∗ 48.7∗ 43No or faulty heads; gol mutations in gene 23 allow growth in lit hosts (CTR5x)Essential; Gol peptide together with E. coli Lit, cleaves host EF- Tu27, 65, 86, 89, 90, 158, 218, 225, 226, 250, 256, 260, 264, 270, 315, 396, 461, 466, 606, 608, 684, 719, 754, 825, 841, 854, 936, 1021, 1093, 1094, 1119, 1231
segDProbable site-specific intron-like DNA endonuclease25.6Nonessential490, 988
24 = osPrecursor of head vertex subunit47.0∗ 46No or faulty heads, osmotic shock resistanceEssential; bypassed by certain gene 23 mutations8, 76, 89, 250, 262, 264, 396, 461, 606, 608, 634, 719, 1114a; G. Yasuda, G. A. Churchill, M. Parker, and D. Moorey, personal communication
rnlB = 24.1Second RNA ligase37.6?426
hoc = ephLarge outer capsid protein40.4Unstable capsidsAuxiliary89, 167, 164, 168, 461, 462, 496, 916, 917, 1205
inh = lipMinor capsid protein; inhibitor of gp21 protease25.6Auxiliary496
segEProbable site-specific intron-like DNA endonuclease22.9Nonessential489, 490, 988
uvsW = darRNA-DNA- and DNA-helicase; DNA-dependent ATPase67.5UV sensitive; fail to unwind R-loops; suppress T4 59 uvsX, uvsY, and 46 mutationsAuxiliary132, 195, 196, 207, 208, 212, 244, 722, 737, 768, 769, 1061, 1191, 1197, 1199, 1222, 1240
uvsY = fdsBssDNA binding, recombination and repair protein; helper of UvsX, inhibitor of endoVII15.8UV sensitive; recombination-deficient; repair-deficient, DNA arrest; suppress T4 49 mutationsAuxiliary25, 44, 82, 182, 183, 195, 212, 213, 232, 357, 358, 380, 387, 392, 522, 542, 548, 589, 723, 724, 739, 768, 769, 1013, 1047, 1054, 1055, 1060, 1061, 1138, 1191, 1199, 1210, 1225, 1222, 1223, 1240
oriF = oriuvsYDNA replication origin; cis-acting sequences in genes uvsY, uvsY.-1 and uvsY.-2; primer transcript same as uvsY, uvsY.-1 and uvsY.-2 transcriptNo DNA synthes from oriFAuxiliary46, 133, 357, 378, 563, 574, 573, 576, 577, 678, 724, 779, 830, 1109, 1215
25Base plate wedge subunit15.1Defective tailsEssential186, 249, 250, 264, 356, 358, 357, 530, 531, 532, 540, 822, 819, 1057, 1155, 1157; B. Szewczyk and J. Nieradko, personal communication; E. Tourkin and B. Poglozov,
26Base plate hub subunit23.9Defective tailsEssential186, 250, 264, 357, 531, 540, 567, 820, 958, 1108, 1157, 1240
26Internal in-frame translation initiation12?357, 823
26"Internal out-of-frame translation initiation10.9?1108
51Base plate hub assembly catalyst?29.3Defective tailsEssential186, 249, 250, 264, 357, 540, 567, 821, 958, 1157; Szewczyk and Nieradko, personal communication
27Base plate hub subunit44.5Defective tails; permit plating of fiberless phageEssential104, 186, 193, 249, 250, 264, 532, 1157, 1240
33Protein connecting gp45 and gp55, to allow transcription by RNA polymerase from late promoters12.8No late RNA synthesisEssential97, 98, 109, 142, 264, 371, 404, 405, 436, 552, 786, 895, 1038, 1173, 1175, 1181, 1185, P. Williams, J. D. Mckinney, K. d'Acci, R. H. Drivdahl, C. Spaulding, J. Gleckler, and E. M. Kutter, unpublished data
dsbAdsDNA binding protein10.4Facilitates some late RNA synthesisAuxiliary142, 303, 371, 372, 786, 995
rnh = dasRNase H; 5′ to 3′ DNase; yeast FEN homologue35.6Defective processing of Okazaki fragments; das mutations suppress T4 46, 47 and uvsX mutationsAuxiliary41, 71, 72, 73, 142, 371, 372, 389, 402, 427, 429, 584, 731, 800, 826, 1139
34Proximal tail fiber subunit140.4Fiberless particlesEssential153, 217, 221, 248, 250, 264, 371, 391, 401, 538, 539, 920, 974, 1114a, 1148, 1190, 1187, 1189
oriG = ori34DNA replication origin; primer transcript in opposite orientation of 34 transcriptNo DNA synthesis from oriGAuxiliary55, 221, 573, 574, 577
35Tail fiber hinge40.1Fiberless particlesEssential153, 217, 248, 250, 264, 401, 538, 539, 920, 974, 1118, 1187, 1189, 1190
36Small distal tail fiber subunit23.3Fiberless particlesEssential153, 217, 248, 250, 264, 401, 538, 539, 840, 920, 1114a, 1187, 1189, 1190
37Large distal tail fiber subunit109.2Fiberless particles, host rangeEssential153, 217, 248, 250, 264, 390, 391, 401, 538, 539, 745, 751, 752, 840, 920, 933, 934, 1023, 1067, 1070, 1114a, 1187, 1189, 1190
38Assembly catalyst of distal tail fiber22.3Fiberless particlesEssential217, 248, 250, 264, 390, 391, 401, 751, 920, 933, 1118, 1187, 1189, 1190
t = rV = stIIHolin, inner membrane pore protein, affects lysis timing and inhibition25.2Affect lysis by e lysozyme; suppress T4 rII and 63 mutationsEssential2, 3, 4, 235, 374, 483, 583, 749, 851, 932
asiAProtein that binds to host σ70, inhibits interaction with −35 regions of classical promoters, and facilitates interaction with T4 MotA protein10.6Defective middle mode, and (indirectly) late transcriptionAlmost essential109, 177, 180, 419, 420, 425, 552, 610, 741, 786, 847, 848, 849, 852, 858, 977, 989, 1038-1040, 1043, 1103, 1104
arnInhibitor of MrcBC restriction nuclease10.9Auxiliary140, 215; T. Djavakhishvili, N. Mzavia, A. Poglazov, and E. Kutter, unpublished data
motA = sipActivator of middle promoters; dsDNA binding protein specific for mot boxes23.6Defective middle mode transcription; suppress rII-defects in λ lysogens; affects interaction with σ70 and AsiAAlmost essential109, 156, 176, 177, 275, 276, 277, 293, 321, 375, 417, 419, 420, 430, 477, 552, 686, 692, 706, 773, 848, 963, 987, 1043, 1106, 1107, 1109
52DNA topoisomerase subunit; membrane-associated protein50.6DNA delayEssential; temperatures below 25°C; inhibition of host topoisomerase IV with novobiocin184, 295, 296, 297, 445, 451, 432, 447, 571, 577, 654, 708, 801, 834, 941, 1037, 1047, 1059, 1216, 1236
acMembrane protein5.5Acriflavine resistantAuxiliary161, 861, 935, 999, 1143
ama = rs5.4Acriflavine resistantAuxiliary161, 894
stpPeptide modulating host restriction system3.18Suppress pseT mutationsAuxiliary161, 203, 204, 513, 514, 515, 859, 1021
ndd = D2bProtein that disrupts host nucleoid; binds to host HU16.9Nucleoid disruption defectiveAuxiliary; CT447101, 102, 103, 161, 550, 551, 1016, 1017, 1018
pla262UnknownCT262161, 204
denBEndonuclease IV, single-strand-specific endonuclease21.2Allow progeny production of T4 with dC-containing DNAAuxiliary138, 140, 204, 1123; H. Krisch, personal communication; M. Saunders and K. Kreuter, personal communication
rIIBMembrane-associated protein; affects host membrane ATPase35.5Rapid lysis; suppresses T4 30 and some 32 mutationsAuxiliary; rex+ λ lysogens; P2-like HK239 lysogen; tabR2, 3, 4, 56, 59, 106, 121, 159, 181, 191, 224, 292, 293, 365, 441, 504, 503, 810, 834, 851, 874, 1021, 1059, 1160
  • a Genes are listed by the currently used names, followed by alternative designations in the literature.

  • b Gene products processed into smaller peptides are indicated (∗) with the sizes or size range following the principal product.

  • c Because the distinction between “essential” and “nonessential” is not always obvious, when mutants have not been tested under all possible growth conditions or in all possible hosts, some “nonessential” genes are noted as “auxiliary.” Where known, restrictive hosts or plating conditions for mutant genes are noted.