Repressor LexA; Represses a number of genes involved in the response to DNA damage (SOS response), including recA and lexA. Has been shown to bind to the 14 bp palindromic sequence 5'-CGAACNNNNGTTCG-3'. In the presence of single-stranded DNA, RecA interacts with LexA causing an autocatalytic cleavage which disrupts the DNA-binding part of LexA, leading to derepression of the SOS regulon and eventually DNA repair.

Probable DNA polymerase I PolA; In addition to polymerase activity, this DNA polymerase exhibits 3'-5' and 5'-3' exonuclease activity; Belongs to the DNA polymerase type-A family.

DNA repair protein RadA (DNA repair protein SMS); DNA-dependent ATPase involved in processing of recombination intermediates, plays a role in repairing DNA breaks. Stimulates the branch migration of RecA-mediated strand transfer reactions, allowing the 3' invading strand to extend heteroduplex DNA faster. Binds ssDNA in the presence of ADP but not other nucleotides, has ATPase activity that is stimulated by ssDNA and various branched DNA structures, but inhibited by SSB. Does not have RecA's homology-searching function. Belongs to the RecA family. RadA subfamily.

DNA-directed RNA polymerase subunit beta; DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates.

Probable DNA polymerase IV DinX (pol IV 1) (DNA nucleotidyltransferase (DNA-directed)); Poorly processive, error-prone DNA polymerase involved in untargeted mutagenesis. Copies undamaged DNA at stalled replication forks, which arise in vivo from mismatched or misaligned primer ends. These misaligned primers can be extended by PolIV. Exhibits no 3'-5' exonuclease (proofreading) activity. May be involved in translesional synthesis, in conjunction with the beta clamp from PolIII (By similarity).

DNA topoisomerase 1; Releases the supercoiling and torsional tension of DNA, which is introduced during the DNA replication and transcription, by transiently cleaving and rejoining one strand of the DNA duplex. Introduces a single-strand break via transesterification at a target site in duplex DNA. The scissile phosphodiester is attacked by the catalytic tyrosine of the enzyme, resulting in the formation of a DNA-(5'-phosphotyrosyl)-enzyme intermediate and the expulsion of a 3'-OH DNA strand. The free DNA strand then undergoes passage around the unbroken strand, thus removing DNA super [...]

Probable 5'-3' exonuclease; 5'-3' exonuclease acting preferentially on double-stranded DNA.

Crossover junction endodeoxyribonuclease RuvC; Nuclease that resolves Holliday junction intermediates in genetic recombination. Cleaves the cruciform structure in supercoiled DNA by nicking to strands with the same polarity at sites symmetrically opposed at the junction in the homologous arms and leaves a 5'-terminal phosphate and a 3'-terminal hydroxyl group (By similarity).

Probable ATP-dependent DNA helicase II UvrD1; DNA-dependent ATPase, acting on dsDNA with a 3'-ssDNA tail, unwinding with 3'-to 5'-polarity. A minimal tail of 18 nt is required for activity. Also highly efficient on nicked DNA. Involved in the post-incision events of nucleotide excision repair, as well as in nitrosative and oxidative stress response and possibly in persistence in the host. Inhibits RecA-mediated DNA strand exchange; this does not require ATPase activity. When combined with UvrA greatly inhibits RecA- mediated DNA strand exchange; Belongs to the helicase family. UvrD sub [...]