Summary

Bacterial extracellular solute-binding protein

This family also includes the bacterial extracellular solute-binding protein family POTD/POTF.

Literature references

Spurlino JC, Lu GY, Quiocho FA; , J Biol Chem 1991;266:5202-5219.: The 2.3-A resolution structure of the maltose- or maltodextrin-binding protein, a primary receptor of bacterial active transport and chemotaxis. PUBMED:2002054
Bruns CM, Nowalk AJ, Arvai AS, McTigue MA, Vaughan KG, Mietzner TA, McRee DE; , Nat Struct Biol 1997;4:919-924.: Structure of Haemophilus influenzae Fe(+3)-binding protein reveals convergent evolution within a superfamily. PUBMED:9360608
Vassylyev DG, Tomitori H, Kashiwagi K, Morikawa K, Igarashi K; , J Biol Chem 1998;273:17604-17609.: Crystal structure and mutational analysis of the Escherichia coli putrescine receptor. Structural basis for substrate specificity. PUBMED:9651355
Tam R, Saier MH Jr; , Microbiol Rev 1993;57:320-346.: Structural, functional, and evolutionary relationships among extracellular solute-binding receptors of bacteria. PUBMED:8336670

InterPro entry IPR006059

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 and a high affinity periplasmic solute-binding protein. In Gram-positive bacteria, which are surrounded by a single membrane and therefore have 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 through 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 of clusters, which generally correlate with the nature of the solute bound. Family 1 currently includes the periplasmic proteins maltose/maltodextrin-binding proteins of Enterobacteriaceae (gene malE) PUBMED:7853407 and Streptococcus pneumoniae malX; multiple oligosaccharide binding protein of Streptococcus mutans (gene msmE); Escherichia coli glycerol-3-phosphate-binding protein; Serratia marcescens iron-binding protein (gene sfuA) and the homologous proteins (gene fbp) from Haemophilus influenzae and Neisseria; and the E. coli thiamine-binding protein (gene tbpA).

Clan

This family is a member of clan PBP (CL0177), which contains the following 15 members:

Bug DUF178 HisG Lig_chan-Glu_bd Lipoprotein_8 Lipoprotein_9 LysR_substrate Mycoplasma_p37 NMT1 OpuAC SBP_bac_1 SBP_bac_3 SBP_bac_5 SBP_bac_7 Transferrin

Gene Ontology

Molecular function	transporter activity (GO:0005215)
Biological process	transport (GO:0006810)

External database links

HOMSTRAD:	PotD SBP_bacterial_1
PANDIT:	PF01547
PROSITE:	PDOC00796
SCOP:	3mbp
SYSTERS:	SBP_bac_1
Transporter classification:	3.A.1

Domain organisation

Below is a listing of the unique domain organisations or architectures in which this domain is found. More...

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Alignments

There are various ways to view or download the sequence alignments that we store. You can use a sequence viewer to look at either the seed or full alignment for the family, or you can look at a plain text version of the sequence in a variety of different formats. More...

View options

Alignment:	Seed (129) Full (14015) NCBI (17061) Metagenomics (8020)
Viewer:

Formatting options

Alignment:	Seed (129) Full (14015)
Format:
Order:	Tree Alphabetical
Sequence:	Inserts lower case All upper case
Gaps:
Download/view:	Download View

Download options

Very large alignments can often cause problems for the formatting tool above. If you find that downloading or viewing a large alignment is problematic, you can also download a gzip-compressed, Stockholm-format file containing the seed or full alignment for this family.

You can also download a FASTA format file containing the full-length sequences for all sequences in the full alignment.

The main seed and full alignments are generated using sequences from the UniProt sequence database. However, we also generate alignments using sequences from the NCBI sequence database and the "metaseq" metagenomics dataset.

You can view alignments from these two additional datasets using the form above, or you can download alignments of NCBI or metagenomics sequences, as gzip-compressed files.

Pfam alignments:	Seed (129) Full (14015) NCBI (17061) Metagenomics (8020)
Full length sequences	Full-sequences (14015)

External links

MyHits provides a collection of tools to handle multiple sequence alignments. For example, one can refine a seed alignment (sequence addition or removal, re-alignment or manual edition) and then search databases for remote homologs using HMMER2.

HMM logo

HMM logos is one way of visualising profile HMMs. Logos provide a quick overview of the properties of an HMM in a graphical form. You can see a more detailed description of HMM logos and find out how you can interpret them here. More...

Trees

This page displays the phylogenetic tree for this family. We use FastTree to calculate neighbour join trees with a local bootstrap based on 100 resamples (shown next to the tree nodes). FastTree calculates approximately-maximum-likelihood phylogenetic trees from our seed or full alignments.

Note: You can also download the data files for the seed, full, NCBI or metagenomics trees.

Curation and family details

This section shows the detailed information about the Pfam family. You can see the definitions of many of the terms in this section in the glossary and a fuller explanation of the scoring system that we use in the scores section of the help pages.

Curation

Seed source:

Pfam-B_269 (release 4.0)

Previous IDs:

SBP_bacterial_1;

Type:

Family

Author:

Bateman A, Griffiths-Jones SR

Number in seed:

129

Number in full:

14015

Average length of the domain:

262.20 aa

Average identity of full alignment:

12 %

Average coverage of the sequence by the domain:

67.97 %

HMM information

HMM build commands:

build method: hmmbuild -o /dev/null HMM SEED

search method: hmmsearch -Z 9421015 -E 1000 HMM pfamseq

Model details:

Parameter	Sequence	Domain
Gathering cut-off	20.5	15.0
Trusted cut-off	20.5	15.0
Noise cut-off	20.4	14.9

Model length:

314

Family (HMM) version:

18

Download:

download the raw HMM for this family

Species distribution

Tree controls

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The tree shows the occurrence of this domain across different species. More...

Species trees

We show the species tree in one of two ways. For smaller trees we try to show an interactive representation, which allows you to select specific nodes in the tree and view them as an alignment or as a set of Pfam domain graphics.

Unfortunately we have found that there are problems viewing the interactive tree when the it becomes larger than a certain limit. Furthermore, we have found that Internet Explorer can become unresponsive when viewing some trees, regardless of their size. We therefore show a text representation of the species tree when the size is above a certain limit or if you are using Internet Explorer to view the site.

If you are using IE you can still load the interactive tree by clicking the "Generate interactive tree" button, but please be aware of the potential problems that the interactive species tree can cause.

Interactive tree

For all of the domain matches in a full alignment, we count the number that are found on all sequences in the alignment. This total is shown in the purple box.

We also count the number of unique sequences on which each domain is found, which is shown in green. Note that a domain may appear multiple times on the same sequence, leading to the difference between these two numbers.

Finally, we group sequences from the same organism according to the NCBI code that is assigned by UniProt, allowing us to count the number of distinct sequences on which the domain is found. This value is shown in the pink boxes.

We use the NCBI species tree to group organisms according to their taxonomy and this forms the structure of the displayed tree. Note that in some cases the trees are too large (have too many nodes) to allow us to build an interactive tree, but in most cases you can still view the tree in a plain text, non-interactive representation. Those species which are represented in the seed alignment for this domain are highlighted.

You can use the tree controls to manipulate how the interactive tree is displayed:

show/hide the summary boxes
highlight species that are represented in the seed alignment
expand/collapse the tree or expand it to a given depth
select a sub-tree or a set of species within the tree and view them graphically or as an alignment
save a plain text representation of the tree

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Interactions

There are 3 interactions for this family. More...

BPD_transp_1 SBP_bac_1 Ribosomal_L7Ae

Structures

For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the MSD 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_1 domain has been found.

Loading structure mapping...

Family: SBP_bac_1 (PF01547)

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