>TIGR02138 phosphate_pstC phosphate ABC transporter, permease protein PstC; InterPro: IPR011864 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). The typical operon for the high affinity inorganic phosphate ABC transporter encodes an ATP-binding protein, a phosphate-binding protein, and two permease proteins. This family describes PstC, which is homologous to PstA (IPR005672 from INTERPRO). In the Escherichia coli, this transport system is induced when the concentration of extrallular inorganic phosphate is low. A constitutive, lower affinity transporter operates otherwise.; GO: 0005315 inorganic phosphate transmembrane transporter activity, 0006817 phosphate transport, 0016021 integral to membrane.

Probab=99.33 E-value=5.6e-08 Score=67.34 Aligned_cols=281 Identities=20% Similarity=0.296 Sum_probs=159.6 Q ss_pred HHHHHHHHHHHHHHHHHHHHHHHHHHHHHCCCCCCCHHCC----CCCCCCCCCCCCCCCCCCHHH-HHHHHHHHHHHHHH Q ss_conf 9999999999999999999999999999728877812138----899844375422356865269-99999999999999 Q gi|254780171|r 26 NISVQIILALLLTVIFLWCVNNVYNNMEKSNLSLGIGFLS----ERAGFEIDQGIVPYTSDSSYA-TAILVGFVNTFWLA 100 (398) Q Consensus 26 ~~~~Q~~~~~~~~~~~~~l~~n~~~nl~~~gi~~gf~FL~----~~agf~I~~~~i~y~~~~sy~-~a~~vGl~NTl~va 100 (398) T Consensus 8 ~~~~~~~~~~~~~~i~~fl~~~a~~~f~~~g~s-~~~f~~~~~W~~~~~---~~~a~~p~~~~yG~l~~i---~GTl~~~ 80 (317) T TIGR02138 8 LLIAAVIIVLVLLLIVLFLLIEAIPAFEKNGIS-LLNFLTGTVWDPDSK---GAEADTPVQEQYGALPLI---VGTLITS 80 (317) T ss_pred HHHHHHHHHHHHHHHHHHHHHHHHHHHHHCCCC-CEEEEECCCCCCCCC---CCCCCCCCHHHHHHHHHH---HHHHHHH T ss_conf 999999999999999999999778888745874-000143120055433---101578730245669999---9999999 Q ss_pred HHHHHHHHHHHHHHHHH--HHCCCHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHCCCHHHHHHCCCCEEEEECCCCC Q ss_conf 99999999999999999--6264246787799999999501469999999999873012103444103720352010003 Q gi|254780171|r 101 FSGMIPATIIGTLVGAG--RLSANKLVAWICRVYVEVFRNIPPLVVIFFLYKSVLSVLPIPDHSIVLPFGMFLNNRGLSF 178 (398) Q Consensus 101 ~~givlatiLG~~iGi~--RlS~N~ll~~la~~YVE~~RN~PLLlql~fwy~~v~~~lP~~~~~~~~~~~~flsnRGL~i 178 (398) T Consensus 81 ~~A~liA~P~~i~~Aif~~e~aP~~~~~~l~~~-~ELLAgIPSVvYG~---wG~~~l~P~l~~~~~~~----~~~----- 147 (317) T TIGR02138 81 LIAILIAVPVGIGIAIFLSEIAPKRVKSVLKPV-VELLAGIPSVVYGF---WGLFVLVPFLKDHFQPF----LGS----- 147 (317) T ss_pred HHHHHHHHHHHHHHHHHHHHHCCHHHHHHHHHH-HHHHHHHHHHHHHH---HHHHHHHHHHHHHHHHH----HHH----- T ss_conf 999999999999999999985251135699999-99972235999999---99999999999988678----653----- Q ss_pred CCCCCCCCHHHHHHHHHHHHHHHHHHHHHHHHHHHHHCCCCCCEEEEEEECCHHHHHHHHHHHHHHHHHHHHCCCCCCCC Q ss_conf 54535567004688778899999999999999864311223320455421010355899976544433221001311126 Q gi|254780171|r 179 PTLTMDTNAKIFVFSFVLGIVLSLFATRLSRHFHEKTGKALPLLYISTFLIFGLPTLVLIALKYQLHFDKPVLGQFNFIG 258 (398) Q Consensus 179 P~p~~~~g~~~~l~~lilaiila~~l~~~a~~~~~~tg~~~~~~~~~~~~~~~~p~l~~~~~~~~~~~~~p~l~~f~~~g 258 (398) T Consensus 148 -----------------------------------------------------------------~~~~iP~~~~~~~~~ 162 (317) T TIGR02138 148 -----------------------------------------------------------------NFGWIPLFGQLFSGP 162 (317) T ss_pred -----------------------------------------------------------------HCCCCCCCCCCCCCC T ss_conf -----------------------------------------------------------------135323212236899 Q ss_pred CCCCCHHHHHHHHHHHHHHHHHHHHHHHHHHHHCCHHHHHHHHHHCCCHHHHHHHHHHHHHHHHHHHHHH-------HHH Q ss_conf 8214878999999999997787999999999834636789998968998998889876899999741047-------899 Q gi|254780171|r 259 GSTVSPEFMSLYIALSCYTAAFIAEIVRSGLIAVPRGQMEAAIALGLTHRKATRLVLLPQAMRSIIPPLT-------SQY 331 (398) Q Consensus 259 G~~l~p~f~a~~iaL~l~taAyiaEivR~gI~sVpkGQ~EAA~aLGls~~q~~r~VIlPQAlR~~iP~l~-------nq~ 331 (398) T Consensus 163 ~~G~--~~L~a~~vL~IMIlPt~as~s~D~~~~VP~~~kea~~ALGAT~wetI~~v~lP~a~~GIv~a~~LglGRAlGET 240 (317) T TIGR02138 163 PNGY--GLLTAGIVLAIMILPTIASISRDALRAVPRSYKEASLALGATKWETIRKVILPAARSGIVGAVVLGLGRALGET 240 (317) T ss_pred CCHH--HHHHHHHHHHHHHHHHHHHHHHHHHHHCCHHHHHHHHHHCCCHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH T ss_conf 8316--89999999999999999999999997355678889877068604335553320002189999999999999999 Q ss_pred --HHHHHHH--HHH--HHHHHHHH-HH-HHHHHHHCCC-------CHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH Q ss_conf --9999754--999--99999999-99-9999983137-------75899999999999999999999999967874 Q gi|254780171|r 332 --LNLLKNS--SLA--VAVGFADL-VS-VGGTIINQTG-------QAIEIILIWMFIYLSLSIMIALFMNRLNAKIA 393 (398) Q Consensus 332 --i~l~K~S--SLa--~~Ig~~dl-~~-~~~~~~~~t~-------~~~e~~~i~~~~Yl~isl~iS~~~n~~~rr~~ 393 (398) T Consensus 241 mAV~mv~Gn~p~~~~~~~~~~f~~~~~T~~~~Ia~~~g~a~~g~~~~~~aL~~~glvLfvitl~~n~~~~~i~~~~~ 317 (317) T TIGR02138 241 MAVAMVIGNAPSLNRPIPLNLFSPYGTTITSLIANEFGEASGGNSVHVSALFALGLVLFVITLLVNILARYIVRRRK 317 (317) T ss_pred HHHHHHHCCCCCCCCCCHHCCHHHHHHHHHHHHHHHCCCCCCCCCHHHHHHHHHHHHHHHHHHHHHHHHHHHHHCCC T ss_conf 99999972432344441202233568999999985066668884268999999999999999999999999853069

HHsearch alignment for GI: 254780171 and conserved domain: TIGR02138