>TIGR00630 uvra excinuclease ABC, A subunit; InterPro: IPR004602 ABC transporters belong to the ATP-Binding Cassette (ABC) superfamily, which uses the hydrolysis of ATP to energize diverse biological systems. ABC transporters are minimally constituted of two conserved regions: a highly conserved ATP binding cassette (ABC) and a less conserved transmembrane domain (TMD). These regions can be found on the same protein or on two different ones. Most ABC transporters function as a dimer and therefore are constituted of four domains, two ABC modules and two TMDs. ABC transporters are involved in the export or import of a wide variety of substrates ranging from small ions to macromolecules. The major function of ABC import systems is to provide essential nutrients to bacteria. They are found only in prokaryotes and their four constitutive domains are usually encoded by independent polypeptides (two ABC proteins and two TMD proteins). Prokaryotic importers require additional extracytoplasmic binding proteins (one or more per systems) for function. In contrast, export systems are involved in the extrusion of noxious substances, the export of extracellular toxins and the targeting of membrane components. They are found in all living organisms and in general the TMD is fused to the ABC module in a variety of combinations. Some eukaryotic exporters encode the four domains on the same polypeptide chain . The ABC module (approximately two hundred amino acid residues) is known to bind and hydrolyze ATP, thereby coupling transport to ATP hydrolysis in a large number of biological processes. The cassette is duplicated in several subfamilies. Its primary sequence is highly conserved, displaying a typical phosphate-binding loop: Walker A, and a magnesium binding site: Walker B. Besides these two regions, three other conserved motifs are present in the ABC cassette: the switch region which contains a histidine loop, postulated to polarize the attaching water molecule for hydrolysis, the signature conserved motif (LSGGQ) specific to the ABC transporter, and the Q-motif (between Walker A and the signature), which interacts with the gamma phosphate through a water bond. The Walker A, Walker B, Q-loop and switch region form the nucleotide binding site , , . The 3D structure of a monomeric ABC module adopts a stubby L-shape with two distinct arms. ArmI (mainly beta-strand) contains Walker A and Walker B. The important residues for ATP hydrolysis and/or binding are located in the P-loop. The ATP-binding pocket is located at the extremity of armI. The perpendicular armII contains mostly the alpha helical subdomain with the signature motif. It only seems to be required for structural integrity of the ABC module. ArmII is in direct contact with the TMD. The hinge between armI and armII contains both the histidine loop and the Q-loop, making contact with the gamma phosphate of the ATP molecule. ATP hydrolysis leads to a conformational change that could facilitate ADP release. In the dimer the two ABC cassettes contact each other through hydrophobic interactions at the antiparallel beta-sheet of armI by a two-fold axis , , , , , . Proteins known to belong to this family are classified in several functional subfamilies depending on the substrate used (for further information see http://www.tcdb.org/tcdb/index.php?tc=3.A.1). During the process of Escherichia coli nucleotide excision repair, DNA damage recognition and processing are achieved by the action of the uvrA, uvrB, and uvrC gene products . The UvrC protein contain 4 conserved regions: a central region which interact with UvrB (Uvr domain), a Helix hairpin Helix (HhH) domain important for 5 prime incision of damage DNA and the homology regions 1 and 2 of unknown function. UvrC homology region 2 is specific for UvrC proteins, whereas UvrC homology region 1 is also shared by few other nucleases.; GO: 0009381 excinuclease ABC activity, 0006289 nucleotide-excision repair, 0009380 excinuclease repair complex.

Probab=91.34  E-value=0.23  Score=28.34  Aligned_cols=122  Identities=21%  Similarity=0.290  Sum_probs=61.5

Q ss_pred             CCCCEEEEECCCCCCCEEEHHHHHCCHHHCC--CCCCEEEEEEECCCCCEEECCHHHCCCEEEEECCCCCHHHHHHHHHH
Q ss_conf             8983454426888887076587512812114--67836898420578873211201148469970787534479999999
Q gi|254780606|r  357 PKRNAIGIELPNETRETVYLRQIIESRSFSH--SKANLALCLGKTISGESVIADLANMPHILVAGTTGSGKSVAINTMIM  434 (744)
Q Consensus       357 pg~~~~~~~~p~~~~~~v~~~~~~~~~~~~~--~~~~l~~~~g~~~~g~~~~~dl~~~PH~lvaG~TgsGKS~~l~~~i~  434 (744)
T Consensus       625 ~G~--~~I~vP~~R~~~~g~r~l~~~gA~~nNLK~i~v~iPLG~---------------~t~iTGVSGSGKSTLind~L~  687 (956)
T TIGR00630       625 SGK--KKIEVPKERRKGNGKRVLTLKGARENNLKNITVSIPLGL---------------FTCITGVSGSGKSTLINDTLY  687 (956)
T ss_pred             CCC--EECCCCCCCCCCCCCEEEEEEECCCCCCCCCEEEECCCE---------------EEEEECCCCCCHHHHHHHHHH
T ss_conf             785--103676311258895599984201056402117740771---------------799974458745777999999


Q ss_pred             HHHHHCCHHHEEEEEECCCCCEECCCCCCCCEEE-------EEE----ECHHHHHHHHHHHHHHHHHHHHHHHHCCCCCH
Q ss_conf             9998568011079997234210001257752000-------044----44178768999999866769999998077867
Q gi|254780606|r  435 SLLYRLRPDECRMIMVDPKMLELSVYDGIPHLLT-------PVV----TNPKKAVMALKWAVREMEERYRKMSHLSVRNI  503 (744)
Q Consensus       435 sl~~~~~p~~~~~~liD~k~~~~~~~~~~ph~~~-------~v~----~~~~~~~~~l~~~~~em~~r~~~~~~~~~~~i  503 (744)
T Consensus       688 ~~~~~~------L~~~~~~~g~~~~I~G~e~lDKvi~iDQsPIGRTPRSNPATYt-------gvFd~IR~LFA~~PeAk~  754 (956)
T TIGR00630       688 PALARR------LNGAKTEPGRYKDIEGLEHLDKVIEIDQSPIGRTPRSNPATYT-------GVFDEIRELFAETPEAKA  754 (956)
T ss_pred             HHHHHH------HHCCCCCCCCCEEEEEECCCCCEEEECCCCCCCCCCCCCCCCC-------CCCHHHHHHHHCCCHHHH
T ss_conf             999999------8527645665203630002384688657743434688643201-------343057776405853787


Q ss_pred             HHHHH
Q ss_conf             99999
Q gi|254780606|r  504 KSYNE  508 (744)
Q Consensus       504 ~~~n~  508 (744)
T Consensus       755 RGY~~  759 (956)
T TIGR00630       755 RGYKP  759 (956)
T ss_pred             CCCCC
T ss_conf             38899