>TIGR02012 tigrfam_recA protein RecA; InterPro: IPR001553 The recA gene product is a multifunctional enzyme that plays a role in homologous recombination, DNA repair and induction of the SOS response . In homologous recombination, the protein functions as a DNA-dependent ATPase, promoting synapsis, heteroduplex formation and strand exchange between homologous DNAs . RecA also acts as a protease cofactor that promotes autodigestion of the lexA product and phage repressors. The proteolytic inactivation of the lexA repressor by an activated form of recA may cause a derepression of the 20 or so genes involved in the SOS response, which regulates DNA repair, induced mutagenesis, delayed cell division and prophage induction in response to DNA damage . RecA is a protein of about 350 amino-acid residues. Its sequence is very well conserved , , among eubacterial species. It is also found in the chloroplast of plants . RecA-like proteins are found in archaea and diverse eukaryotic organisms, like fission yeast, mouse or human. In the filament visualised by X-ray crystallography, ß-strand 3, the loop C-terminal to ß-strand 2, and alpha-helix D of the core domain form one surface that packs against alpha-helix A and ß-strand 0 (the N-terminal domain) of an adjacent monomer during polymerisation [Lusetti and Cox, Annu. Rev. Biochem. 2002. 71:71-100.]. The core ATP-binding site domain is well conserved, with 14 invariant residues. It contains the nucleotide binding loop between ß-strand 1 and alpha-helix C. The Escherichia coli sequence GPESSGKT matches the consensus sequence of amino acids (G/A)XXXXGK(T/S) for the Walker A box (also referred to as the P-loop) found in a number of nucleoside triphosphate (NTP)-binding proteins. Another nucleotide binding motif, the Walker B box is found at ß-strand 4 in the RecA structure. The Walker B box is characterised by four hydrophobic amino acids followed by an acidic residue (usually aspartate). Nucleotide specificity and additional ATP binding interactions are contributed by the amino acid residues at ß-strand 2 and the loop C-terminal to that strand, all of which are greater than 90

Probab=96.25  E-value=0.011  Score=38.84  Aligned_cols=129  Identities=22%  Similarity=0.203  Sum_probs=87.2

Q ss_pred             CCCCCCCHHHHHHHHH--HHHCCCCEEEEECCCCHHHHHHHHHHHHHHHHCCCCEEEECCCCCHHHHHHHHHHHHHCCCC
Q ss_conf             6678511137777765--53016836887068741488999999999630223236411675348999999996302232
Q gi|254781149|r  121 ENPDIKWGLQSVDHLM--GGVQLRELILIGARPSMGKTTFALSTALHMAMSGHGVAFFSLEMDREKLGARALSNLLYPSS  198 (266)
Q Consensus       121 ~~~Gi~TG~~~LD~~~--gG~~~g~LiviaaRP~mGKTa~alnia~~~a~~g~~Vl~fSlEMs~~ql~~R~ls~~t~~~~  198 (266)
T Consensus        32 ~v~~i~tGsl~LD~AlG~GG~P~GRi~EiYGpESsGKTTLal~~iA~~Qk~Gg~~afiDAEHAlD~~YA~~LG-------  104 (322)
T TIGR02012        32 DVEVISTGSLALDLALGVGGLPKGRIIEIYGPESSGKTTLALHVIAEAQKAGGVAAFIDAEHALDPVYAKKLG-------  104 (322)
T ss_pred             CEEEECCCCHHHHHHHCCCCCCCCEEEEEECCCCCCHHHHHHHHHHHHHHCCCEEEEEECHHHCCHHHHHHHC-------
T ss_conf             1002125301343551679898750799854898847899999999997439838998451303778899836-------


Q ss_pred             CCCCHHHCCCCCCCHHHHHHHHHHHHHHHHC---CC-EEECCCCCCH----------HHHHHHHHHHHHHHHHHHH
Q ss_conf             3478555017889989999999999999729---95-4747998898----------9999999999999479998
Q gi|254781149|r  199 SRIPYLNLIRGEINQEQYRISQGICEKLQDF---PL-IIDDRPSPGI----------MEFVHVANGLRNKHTKMVQ  260 (266)
Q Consensus       199 s~I~~~~l~~g~l~~~e~~~i~~a~~~l~~~---pl-~IdD~~~~ti----------~~ira~aR~~k~k~~~~~~  260 (266)
T Consensus       105 --v~~~~L~~sQPd~G--E~ALeI~~~L~rSgAvD~iVvDSVAAL~P~aEieGemgd~~~Gl~ARLMS~ALRKl~g  176 (322)
T TIGR02012       105 --VDIDNLLVSQPDTG--EQALEIAETLVRSGAVDIIVVDSVAALVPKAEIEGEMGDSHVGLQARLMSQALRKLTG  176 (322)
T ss_pred             --CCHHHHEEECCCCC--HHHHHHHHHHHHCCCCEEEEECCCCCCCCHHHCCCCCCCCCCCHHHHHHHHHHHHHHH
T ss_conf             --45247112088871--4699999998723761179973400138712317543544232578889999998887