Assembly architecture and DNA binding of the bacteriophage P22 terminase small subunit.
Morphogenesis of bacteriophage P22 involves the packaging of double-stranded DNA into a preassembled procapsid. DNA is translocated by a powerful virally encoded molecular motor called terminase, which comprises large (gp2, 499 residues) and small (gp3, 162 residues) subunits. While gp2 contains the phosphohydrolase and endonuclease activities of terminase, the function of gp3 may be to regulate specific and nonspecific modes of DNA recognition as well as the enzymatic activities of gp2. Electron microscopy shows that wild-type gp3 self-assembles into a stable and monodisperse nonameric ring. A three-dimensional reconstruction at 18 A resolution provides the first glimpse of P22 terminase architecture and implies two distinct modes of interaction with DNA-involving a central channel of 20 A diameter and radial spikes separated by 34 A. Electromobility shift assays indicate that the gp3 ring binds double-stranded DNA nonspecifically in vitro via electrostatic interactions between the positively charged C-terminus of gp3 (residues 143-152) and phosphates of the DNA backbone. Raman spectra show that nonameric rings formed by subunits truncated at residue 142 retain the subunit fold despite the loss of DNA-binding activity. Difference density maps between gp3 rings containing full-length and C-terminally truncated subunits are consistent with localization of residues 143-152 along the central channel of the nonameric ring. The results suggest a plausible molecular mechanism for gp3 function in DNA recognition and translocation.
Nemecek
Daniel
D
School of Biological Sciences, University of Missouri-Kansas City, Kansas City, MO 64110-2499, USA.
Lander
Gabriel C
GC
Johnson
John E
JE
Casjens
Sherwood R
SR
Thomas
George J
GJ
D017100:Bacteriophage P22 / Q000201:enzymology*; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004706:Endodeoxyribonucleases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D021122:Protein Subunits / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D014764:Viral Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
D004268:DNA-Binding Proteins; D021122:Protein Subunits; D014764:Viral Proteins; D004247:DNA; D004706:Endodeoxyribonucleases; C030894:terminase
J Mol Biol. 1984 Dec 5;180(2):283-300
6096564
J Biol Chem. 2006 Aug 4;281(31):21914-21923
16735502
Biochemistry. 2006 Dec 26;45(51):15259-68
17176048
J Virol. 1985 Aug;55(2):458-65
2991569
Virology. 1991 Aug;183(2):519-38
1853558
J Mol Biol. 2006 Nov 3;363(4):786-99
16987527
Science. 2006 Jun 23;312(5781):1791-5
16709746
J Biol Chem. 2003 Jun 27;278(26):23251-9
12697751
J Biol Chem. 1987 Jun 25;262(18):8845-50
3036832
J Mol Biol. 2007 May 25;369(1):79-94
17428497
Biochemistry. 1999 Mar 30;38(13):4018-27
10194314
Virology. 1991 Dec;185(2):788-94
1962450
J Biol Chem. 2000 Nov 24;275(47):37127-36
10967092
J Mol Biol. 1995 Jan 13;245(2):141-50
7799432
J Virol. 1988 Feb;62(2):387-92
2826803
Biochemistry. 2006 Apr 25;45(16):5180-9
16618107
J Mol Biol. 1978 Jan 25;118(3):365-88
344888
J Mol Biol. 2007 Nov 30;374(3):817-36
17945256
Mol Cell. 2002 May;9(5):981-91
12049735
J Mol Biol. 2006 Apr 21;358(1):67-82
16513134
Science. 1982 Apr 30;216(4545):475-85
7071593
Mol Microbiol. 2002 Sep;45(6):1631-46
12354230
J Mol Biol. 1995 Sep 29;252(4):386-98
7563059
J Struct Biol. 2007 Jan;157(1):201-10
17029845
J Mol Biol. 1999 Jun 4;289(2):249-60
10366503
J Biol Chem. 2000 Nov 10;275(45):35311-9
10930407
J Mol Biol. 1992 Oct 20;227(4):1086-99
1433288
Mol Cell. 2007 Mar 23;25(6):943-9
17386269
Biochemistry. 2001 Feb 27;40(8):2522-9
11327874
J Mol Biol. 1995 Feb 3;245(5):635-44
7844832
Proc Natl Acad Sci U S A. 1967 Feb;57(2):292-5
16591467
Biochemistry. 1975 Nov 4;14(22):4870-6
241390
J Biol Chem. 1997 Feb 7;272(6):3495-501
9013596
J Mol Biol. 1974 Jan 5;85(4):485-500
4853525
J Bacteriol. 2005 Feb;187(3):1091-104
15659686
J Mol Biol. 1996 Dec 20;264(5):954-67
9000623