Summary: Bacterial extracellular solute-binding proteins, family 3
Bacterial extracellular solute-binding proteins, family 3 Provide feedback
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Internal database links
|Similarity to PfamA using HHSearch:||Lig_chan SBP_bac_7 NMT1 Lig_chan-Glu_bd DUF3834 Phosphonate-bd SBP_bac_11 YhfZ_C|
External database links
This tab holds annotation information from the InterPro database.
InterPro entry IPR001638
Bacterial high affinity transport systems are involved in active transport of solutes across the cytoplasmic membrane. The protein components of these traffic systems include one or two transmembrane protein components, one or two membrane-associated ATP-binding proteins (ABC transporters; see INTERPRO) and a high affinity periplasmic solute-binding protein. The latter are thought to bind the substrate in the vicinity of the inner membrane, and to transfer it to a complex of inner membrane proteins for concentration into the cytoplasm.
In Gram-positive bacteria which are surrounded by a single membrane and have therefore no periplasmic region, the equivalent proteins are bound to the membrane via an N-terminal lipid anchor. These homologue proteins do not play an integral role in the transport process per se, but probably serve as receptors to trigger or initiate translocation of the solute throught the membrane by binding to external sites of the integral membrane proteins of the efflux system.
In addition, at least some solute-binding proteins function in the initiation of sensory transduction pathways.
On the basis of sequence similarities, the vast majority of these solute-binding proteins can be grouped [PUBMED:8336670] into eight families or clusters, which generally correlate with the nature of the solute bound.
Family 3 groups together specific amino acids and opine-binding periplasmic proteins and a periplasmic homologue with catalytic activity.
The mapping between Pfam and Gene Ontology is provided by InterPro. If you use this data please cite InterPro.
|Cellular component||outer membrane-bounded periplasmic space (GO:0030288)|
|Molecular function||transporter activity (GO:0005215)|
|Biological process||transport (GO:0006810)|
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Curation and family details
|Number in seed:||483|
|Number in full:||31454|
|Average length of the domain:||223.60 aa|
|Average identity of full alignment:||19 %|
|Average coverage of the sequence by the domain:||63.80 %|
|HMM build commands:||
build method: hmmbuild -o /dev/null --hand HMM SEED
search method: hmmsearch -Z 23193494 -E 1000 --cpu 4 HMM pfamseq
|Family (HMM) version:||15|
|Download:||download the raw HMM for this family|
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We determine these interactions using iPfam, which considers the interactions between residues in three-dimensional protein structures and maps those interactions back to Pfam families. You can find more information about the iPfam algorithm in the journal article that accompanies the website.
For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the PDBe group, to allow us to map Pfam domains onto UniProt sequences and three-dimensional protein structures. The table below shows the structures on which the SBP_bac_3 domain has been found. There are 113 instances of this domain found in the PDB. Note that there may be multiple copies of the domain in a single PDB structure, since many structures contain multiple copies of the same protein seqence.
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