>TIGR02141 modB_ABC molybdate ABC transporter, permease protein; InterPro: IPR011867 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). This entry describes the permease protein, ModB, of the molybdate ABC transporter. This system has been characterised in Escherichia coli , Staphylococcus carnosus Rhodobacter capsulatus and Azotobacter vinlandii . Molybdate is chemically similar to sulphate, thiosulphate, and selenate. These related substrates, and sometimes molybdate itself, can be transported by the homologous sulphate receptor. Some apparent molybdenum transport operons include a permease related to this ModB, although less similar than some sulphate permease proteins and not included in this model.; GO: 0015098 molybdate ion transmembrane transporter activity, 0015689 molybdate ion transport, 0016021 integral to membrane.

Probab=99.79  E-value=1.1e-17  Score=124.89  Aligned_cols=179  Identities=25%  Similarity=0.383  Sum_probs=141.8

Q ss_pred             HHHHHHHHHHHHHHHHHHHHHHHCCCCH-HHHHCCCHHHHHHHHCCCCCHHHHHHHHCCCC--H----------------
Q ss_conf             9999999999788766677642101211-23202350345442012021011000000210--1----------------
Q gi|254780341|r   95 ETLSLVLVSTFISMFIGVPLGVLAAWYP-RFYSIIRLFLDSMQTIPTFVYLIPALVLFGLG--M----------------  155 (281)
Q Consensus        95 ~Tl~~~~~~~~ia~~igiplGi~~~~~~-~~~~~~~p~l~~~~~iP~~v~l~p~i~~fG~g--~----------------  155 (281)
T Consensus         2 LSlk~A~~~Tl~~~~LGi~~A~~La~~~f~gK~~le~L~~LPLVLPPtV~Gf~LL~~fG~~~G~~G~l~~~~~~~Gl~Ft   81 (212)
T TIGR02141         2 LSLKVAVIATLLLLPLGIPVAWLLARSRFRGKSLLEALVTLPLVLPPTVLGFYLLLAFGRNSGPIGKLLELLGISGLVFT   81 (212)
T ss_pred             HHHHHHHHHHHHHHHHHHHHHHHHHHHCCCHHHHHHHHHHCCCCCCCHHHHHHHHHHHCCCCCCHHHHHHHHHCCCHHHH
T ss_conf             79999999999999999999999988617604544644432663563789999999880357407789886506852466


Q ss_pred             -HHHHHHHHHHHHHHHHHHHHHHHHCCCHHHHHHHHHCCCCHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH---
Q ss_conf             -7889999998878999995887412998999999960788201012236886267999999999999999999999---
Q gi|254780341|r  156 -VPGIVATIVFSIPTSVRLTRLGIISTPPILKEAACAFGATPFQVFRKVELPFAIPQIVASLTQTIMLSLSMVVVTA---  231 (281)
Q Consensus       156 -~~~i~a~~i~~~~pi~~~t~~gl~~v~~~~~eaa~~~Gas~~q~l~~V~lP~a~P~i~~Gi~~~~~~~l~~vvia~---  231 (281)
T Consensus        82 ~~g~vlAs~~VSfPl~v~~~~~a~~~~~~~~~~~ArtLGaS~~~~f~~v~LPL~~pG~l~G~v----L~FAR-~LGEFGA  156 (212)
T TIGR02141        82 FAGAVLASVVVSFPLMVRTIRGAFEAVDPDLEEAARTLGASELRVFLKVTLPLAFPGLLAGAV----LSFAR-ALGEFGA  156 (212)
T ss_pred             HHHHHHHHHHHHHHHHHHHHHHHHHHHCHHHHHHHHHHCCCHHHHHHHHHHHHHHHHHHHHHH----HHHHH-HHHHHHH
T ss_conf             999999999999776899999999862712899998827878998999985732899999999----99997-5021134


Q ss_pred             --HHCC------CCHHHHHHHHHHH-HCHHHHHHHHHHHHHHHHHHHHHHHHHHHH
Q ss_conf             --9705------8804999999974-078989999999999999999999987421
Q gi|254780341|r  232 --LVGS------NGLGVPVLRALNT-VDIGRGFESGLCIVILAIILDRLFSIPDPR  278 (281)
Q Consensus       232 --~ig~------~GLG~~i~~a~~~-~~~~~~~~~~l~Iv~lai~lDri~~~~~~r  278 (281)
T Consensus       157 tlm~aGNIpGkT~T~plaIY~~v~~lg~~~~A~~l~l~ll~~s~~~ll~~~~~~~R  212 (212)
T TIGR02141       157 TLMFAGNIPGKTRTIPLAIYDAVESLGDYEAAHLLSLVLLALSLIVLLLVELLNKR  212 (212)
T ss_pred             HHHHCCCCCCCCHHHHHHHHHHHHCCCCHHHHHHHHHHHHHHHHHHHHHHHHHHCC
T ss_conf             43100469796301767788677057886789999999999999999999875059