>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=90.45  E-value=0.22  Score=29.12  Aligned_cols=123  Identities=22%  Similarity=0.331  Sum_probs=68.5

Q ss_pred             HCCHHHHHCCCCCCCCCEEEEECCCCCCCHHHHHHHHHHHHHHCCCCCCCCCCEEEEEECCCCHHHHHHHHHHHCCCCCC
Q ss_conf             41602331011115683365524778861158999999988630246678760699995167767899999851146742
Q gi|254780617|r  147 STGIKAIDSLIPIGRGQRELIIGDRKTGKTSIILDTFLNQKSSHDKGSEKDKVYCIYVAIGQKRSSVARFVKALEDRGAL  226 (509)
Q Consensus       147 ~TGI~~ID~l~pigrGQR~~I~g~~g~GKt~l~~~~I~nq~~~~~~~~~~~~v~~V~~~IGer~~ev~~~~~~l~~~~~~  226 (509)
T Consensus       652 ~nNLK~i~v~iPL--G~~t~iTGVSGSGKSTLind~L~~~~~~~L~----------------~~~~~~g~~~~I~G~e~l  713 (956)
T TIGR00630       652 ENNLKNITVSIPL--GLFTCITGVSGSGKSTLINDTLYPALARRLN----------------GAKTEPGRYKDIEGLEHL  713 (956)
T ss_pred             CCCCCCCEEEECC--CEEEEEECCCCCCHHHHHHHHHHHHHHHHHH----------------CCCCCCCCCEEEEEECCC
T ss_conf             0564021177407--7179997445874577799999999999985----------------276456652036300023


Q ss_pred             CEEEEEEECCCCCHHHHH-H---HHHHHHHHHHHHHCCCCCEEEEEECHHHHHHHHHHHHHHCCCCCC-CCCCCCCCHHH
Q ss_conf             115899728878889999-9---887666666754204688479961647899999875453037875-43337520012
Q gi|254780617|r  227 SYSIVVVASASDPAPMQL-L---APFAGCAMGEYFRDNGYHALIAYDDLQKHAVAYRQLSLLLRRPPG-REAYPGDVFYL  301 (509)
Q Consensus       227 ~~tvvv~a~a~~~~~~r~-~---ap~~a~aiAEyfr~~G~~VLi~~Ddltr~A~a~reisl~~~~pp~-~~gyp~~vf~~  301 (509)
T Consensus       714 DKvi~i----DQsPIGRTPRSNPATYtgv----------------Fd~-------IR~L--FA~~PeAk~RGY~~GRFSF  764 (956)
T TIGR00630       714 DKVIEI----DQSPIGRTPRSNPATYTGV----------------FDE-------IREL--FAETPEAKARGYKPGRFSF  764 (956)
T ss_pred             CCEEEE----CCCCCCCCCCCCCCCCCCC----------------CHH-------HHHH--HHCCCHHHHCCCCCCCEEE
T ss_conf             846886----5774343468864320134----------------305-------7776--4058537873889986146


Q ss_pred             HHHH--HHHHHHCCCCCCCCCEE
Q ss_conf             4678--88875045445887356
Q gi|254780617|r  302 HSRL--LERAAKMSDALGAGSLT  322 (509)
Q Consensus       302 ~s~l--~ERa~~~~~~~g~GSiT  322 (509)
T Consensus       765 NVkGGRCE~C~------GDG~ik  781 (956)
T TIGR00630       765 NVKGGRCEACQ------GDGVIK  781 (956)
T ss_pred             CCCCCCCCCCC------CCCEEE
T ss_conf             58888432426------885478