|Gene:||recG||Accession Numbers: EG10829 (EcoCyc), b3652, ECK3642|
Synonyms: radC, spoV
RecG is a DNA helicase involved in double-strand break repair and protecting against aberrant DNA replication following replication fork collisions.
RecG catalyzes branch migration on forked DNA structures [Courcelle03, Whitby94]. Studies in which double-strand breaks are induced show that double-strand break repair can proceed via two recombination pathways. Both pathways require RecBCD and RecA, but one depends on the resolvase enzyme, RuvABC, while the other instead relies on RecG.
RecG helicase binds the junctions formed as recombinational intermediates (Holliday junctions) and resolves them by promoting branch migration in a process termed "strand extrusion" [Kuzminov99]. RecG shows an affinity for three-way junctions and is thought to resolve them by translocation, disrupting RecA-promoted pairing [McGlynn97].
The regulation of recG has been described. Transcription is induced by the CreBC two component system in minimal medium growth conditions [Avison01]. In ruv mutants, the RecG junction resolution pathway can be stimulated by the expression of RusA, a resolvase whose gene resides on a cryptic prophage [Mandal93, Kuzminov99].
Mutants lacking RecG function allow constitutive stable DNA replication (cSDR or SDR), that is DNA replication in the absence of protein synthesis. They also exhibit an absolute requirement for Pol I DNA polymerase activity. They are lethal in combination with mutants in rnhA, another gene whose absence allows cSDR [Hong95]. recG mutants are somewhat more susceptible to DNA damage [Courcelle03, Whitby94]. In the specific case of UV irradiation, recG mutants lead to a PriA-dependent pathological DNA replication cascade, most likely through repeated generation of new replication forks [Rudolph09]. ΔrecG mutants have a high incidence of extra replication initiation in the terminus area - this replication is the result of PriA-PriB mediated loading of DnaB at a branched DNA structure that forms in the absence of RecG [Rudolph13].
Gene Citations: [Kalman92]
|Map Position: [3,823,233 -> 3,825,314] (82.4 centisomes, 297°)||Length: 2082 bp / 693 aa|
Molecular Weight of Polypeptide: 76.43 kD (from nucleotide sequence)
Unification Links: ASAP:ABE-0011939 , CGSC:307 , DIP:DIP-10653N , EchoBASE:EB0822 , EcoGene:EG10829 , EcoliWiki:b3652 , Mint:MINT-1301344 , ModBase:P24230 , OU-Microarray:b3652 , PortEco:recG , PR:PRO_000023702 , Pride:P24230 , Protein Model Portal:P24230 , RefSeq:NP_418109 , RegulonDB:EG10829 , SMR:P24230 , String:511145.b3652 , UniProt:P24230
Relationship Links: InterPro:IN-FAMILY:IPR001650 , InterPro:IN-FAMILY:IPR004365 , InterPro:IN-FAMILY:IPR004609 , InterPro:IN-FAMILY:IPR011545 , InterPro:IN-FAMILY:IPR012340 , InterPro:IN-FAMILY:IPR014001 , InterPro:IN-FAMILY:IPR027417 , Pfam:IN-FAMILY:PF00270 , Pfam:IN-FAMILY:PF00271 , Pfam:IN-FAMILY:PF01336 , Prosite:IN-FAMILY:PS51192 , Prosite:IN-FAMILY:PS51194 , Smart:IN-FAMILY:SM00487 , Smart:IN-FAMILY:SM00490
In Paralogous Gene Group: 502 (2 members)
|Biological Process:||GO:0032508 - DNA duplex unwinding
GO:0006281 - DNA repair [UniProtGOA11, GOA01]
GO:0006310 - DNA recombination [UniProtGOA11, GOA01]
GO:0006974 - cellular response to DNA damage stimulus [UniProtGOA11]
GO:0010501 - RNA secondary structure unwinding [Gaudet10]
|Molecular Function:||GO:0004003 - ATP-dependent DNA helicase activity
GO:0000166 - nucleotide binding [UniProtGOA11]
GO:0003676 - nucleic acid binding [GOA01]
GO:0003677 - DNA binding [UniProtGOA11]
GO:0004004 - ATP-dependent RNA helicase activity [Gaudet10]
GO:0004386 - helicase activity [UniProtGOA11]
GO:0005524 - ATP binding [UniProtGOA11, GOA01]
GO:0016787 - hydrolase activity [UniProtGOA11]
|Cellular Component:||GO:0005829 - cytosol
GO:0009379 - Holliday junction helicase complex [Lloyd93]
|MultiFun Terms:||information transfer → DNA related → DNA replication|
|Growth Medium||Growth?||T (°C)||O2||pH||Osm/L||Growth Observations|
|LB enriched||Yes||37||Aerobic||6.95||Yes [Gerdes03, Comment 1]|
|LB Lennox||Yes||37||Aerobic||7||Yes [Baba06, Comment 2]|
|M9 medium with 1% glycerol||Yes||37||Aerobic||7.2||0.35||Yes [Joyce06, Comment 3]|
|MOPS medium with 0.4% glucose||Yes||37||Aerobic||7.2||0.22||Yes [Baba06, Comment 2]|
EC Number: 3.6.1.-
The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction in which it was curated.
Reversibility of this reaction is unspecified.
|Conserved-Region||283 -> 448|
|Nucleotide-Phosphate-Binding-Region||296 -> 303|
|Protein-Segment||397 -> 400|
|Mutagenesis-Variant||411 -> 693|
|Conserved-Region||482 -> 628|
10/20/97 Gene b3652 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG10829; confirmed by SwissProt match.
Avison01: Avison MB, Horton RE, Walsh TR, Bennett PM (2001). "Escherichia coli CreBC is a global regulator of gene expression that responds to growth in minimal media." J Biol Chem 276(29);26955-61. PMID: 11350954
Baba06: Baba T, Ara T, Hasegawa M, Takai Y, Okumura Y, Baba M, Datsenko KA, Tomita M, Wanner BL, Mori H (2006). "Construction of Escherichia coli K-12 in-frame, single-gene knockout mutants: the Keio collection." Mol Syst Biol 2;2006.0008. PMID: 16738554
DiazMejia09: Diaz-Mejia JJ, Babu M, Emili A (2009). "Computational and experimental approaches to chart the Escherichia coli cell-envelope-associated proteome and interactome." FEMS Microbiol Rev 33(1);66-97. PMID: 19054114
Gerdes03: Gerdes SY, Scholle MD, Campbell JW, Balazsi G, Ravasz E, Daugherty MD, Somera AL, Kyrpides NC, Anderson I, Gelfand MS, Bhattacharya A, Kapatral V, D'Souza M, Baev MV, Grechkin Y, Mseeh F, Fonstein MY, Overbeek R, Barabasi AL, Oltvai ZN, Osterman AL (2003). "Experimental determination and system level analysis of essential genes in Escherichia coli MG1655." J Bacteriol 185(19);5673-84. PMID: 13129938
Joyce06: Joyce AR, Reed JL, White A, Edwards R, Osterman A, Baba T, Mori H, Lesely SA, Palsson BO, Agarwalla S (2006). "Experimental and computational assessment of conditionally essential genes in Escherichia coli." J Bacteriol 188(23);8259-71. PMID: 17012394
Mandal93: Mandal TN, Mahdi AA, Sharples GJ, Lloyd RG (1993). "Resolution of Holliday intermediates in recombination and DNA repair: indirect suppression of ruvA, ruvB, and ruvC mutations." J Bacteriol 175(14);4325-34. PMID: 8331065
Watt07: Watt RM, Wang J, Leong M, Kung HF, Cheah KS, Liu D, Danchin A, Huang JD (2007). "Visualizing the proteome of Escherichia coli: an efficient and versatile method for labeling chromosomal coding DNA sequences (CDSs) with fluorescent protein genes." Nucleic Acids Res 35(6);e37. PMID: 17272300
Lemke11: Lemke JJ, Sanchez-Vazquez P, Burgos HL, Hedberg G, Ross W, Gourse RL (2011). "Direct regulation of Escherichia coli ribosomal protein promoters by the transcription factors ppGpp and DksA." Proc Natl Acad Sci U S A 108(14);5712-7. PMID: 21402902
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