>TIGR00916 2A0604s01 protein-export membrane protein, SecD/SecF family; InterPro: IPR003335 Secretion across the inner membrane in some Gram-negative bacteria occurs via the preprotein translocase pathway. Proteins are produced in the cytoplasm as precursors, and require a chaperone subunit to direct them to the translocase component. . From there, the mature proteins are either targeted to the outer membrane, or remain as periplasmic proteins. The translocase protein subunits are encoded on the bacterial chromosome. The translocase itself comprises 7 proteins, including a chaperone protein (SecB), an ATPase (SecA), an integral membrane complex (SecCY, SecE and SecG), and two additional membrane proteins that promote the release of the mature peptide into the periplasm (SecD and SecF) . The chaperone protein SecB is a highly acidic homotetrameric protein that exists as a "dimer of dimers" in the bacterial cytoplasm. SecB maintains preproteins in an unfolded state after translation, and targets these to the peripheral membrane protein ATPase SecA for secretion . Together with SecY and SecG, SecE forms a multimeric channel through which preproteins are translocated, using both proton motive forces and ATP-driven secretion. The latter is mediated by SecA. The structure of the Escherichia coli SecYEG assembly revealed a sandwich of two membranes interacting through the extensive cytoplasmic domains . Each membrane is composed of dimers of SecYEG. The monomeric complex contains 15 transmembrane helices. This family consists of various prokaryotic SecD and SecF protein export membrane proteins. The SecD and SecF equivalents of the Gram-positive bacterium Bacillus subtilis are jointly present in one polypeptide, denoted SecDF, that is required to maintain a high capacity for protein secretion. Unlike the SecD subunit of the pre-protein translocase of E. coli, SecDF of B. subtilis was not required for the release of a mature secretory protein from the membrane, indicating that SecDF is involved in earlier translocation steps . Comparison with SecD and SecF proteins from other organisms revealed the presence of 10 conserved regions in SecDF, some of which appear to be important for SecDF function. Interestingly, the SecDF protein of B. subtilis has 12 putative transmembrane domains. Thus, SecDF does not only show sequence similarity but also structural similarity to secondary solute transporters .; GO: 0008565 protein transporter activity, 0015628 protein secretion by the type II secretion system, 0015627 type II protein secretion system complex.

Probab=100.00  E-value=0  Score=291.44  Aligned_cols=182  Identities=31%  Similarity=0.636  Sum_probs=165.6

Q ss_pred             CHHHHHHHHHHHHHCCCCCCCCCCCCCCCCCHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH-HHHH
Q ss_conf             023567887775410124443333211121013578998457999999999999999999999899999999999-9999
Q gi|254780925|r  629 VAQTRVLEMVKKKITEIVPLSTIQNTEIVGPKISRELIRKGIVGVIISAIAMLIYIWIRFKWYFALGAITTLILD-ITKT  707 (833)
Q Consensus       629 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~v~~~~~~~~~~~~~~a~~~al~~I~i~i~~rf~~~~~i~aiial~~~-v~~~  707 (833)
T Consensus        61 ~~A~~LA~~Lr~G--aLp~~~~~~e~r~iGp~lG~~~~~~g~~A~~~~l~~v~~Y~~~ry~~~~~~a~~~~l~~Dl~~~~  138 (247)
T TIGR00916        61 EEAQDLALLLRSG--ALPAPIKILEERTIGPSLGAELIRAGILALLIALVLVLLYMLLRYEWRGAIAAIALLVHDLVILI  138 (247)
T ss_pred             HHHHHHHHHHHHH--HCCCCEEEEEEEECCHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH
T ss_conf             9999999999874--12567178610344755568999999999999999999999999999999999999999999999


Q ss_pred             HHHHHHHC-CCCCHHHHHHHHHHHHHHHCCEEEEEEEEHHHHH--HCCCCCCHHHHHHHHHHHHHHHHHHHHHHHHHHHH
Q ss_conf             99999975-7145699999999997533574788721035555--05779998999999998777999999999999999
Q gi|254780925|r  708 LGFFALFG-IEFNLTAVAAVLTLIGYSVNDKVVVYDRMRKNMK--LYTTSISFRDLIDKSINETLGRSVYTSMAAFISVL  784 (833)
Q Consensus       708 ~g~~~~~g-~~~~~~~i~~~l~iiG~svd~~I~~~~RirE~~~--~~~~~~~~~~~v~~~~~~~~~~~i~ts~tt~~~~~  784 (833)
T Consensus       139 ~a~~s~~~G~~l~L~~iAgll~~iG~svdd~VviFdRiREelr~~k~-~g~~~~~a~~~g~~~tl~ri~~t~~TTlla~~  217 (247)
T TIGR00916       139 LAVLSLFGGATLTLPGIAGLLLIIGYSVDDTVVIFDRIREELRDIKY-KGRTLREAINLGFNQTLSRIIDTNVTTLLAAL  217 (247)
T ss_pred             HHHHHHHCCEEECHHHHHHHHHHHHHHHHCEEEEECCCHHHHHHHHH-CCCCHHHHHHHHHHHHHHHHHHHHHHHHHHHH
T ss_conf             99999875900278999999999978764554787350888886411-48979999998899999998998699999999


Q ss_pred             HHHHCCCHHHH-HHHHHHHHHHHHHHHHHH
Q ss_conf             99970534356-638999999999999999
Q gi|254780925|r  785 PMAVWGGSVIG-SFAIPMAFGIVVAASSSI  813 (833)
Q Consensus       785 ~l~~~~~~~~~-~f~~~~~~gvi~~~~~si  813 (833)
T Consensus       218 ~L~~fG~g~ik~gFal~l~iG~~~g~ySsi  247 (247)
T TIGR00916       218 ALFVFGGGAIKKGFALTLLIGVIAGTYSSI  247 (247)
T ss_pred             HHHHHHCCHHHHHHHHHHHHHHHHHHHCCC
T ss_conf             999971013431147878788788644049