Summary: Single-strand binding protein family
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This is the Wikipedia entry entitled "Single-stranded binding protein". More...
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Single-strand binding protein family Provide feedback
This family includes single stranded binding proteins and also the primosomal replication protein N (PriB). PriB forms a complex with PriA, PriC and ssDNA.
Literature references
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Raghunathan S, Ricard CS, Lohman TM, Waksman G; , Proc Natl Acad Sci U S A 1997;94:6652-6657.: Crystal structure of the homo-tetrameric DNA binding domain of Escherichia coli single-stranded DNA-binding protein determined by multiwavelength x-ray diffraction on the selenomethionyl protein at 2.9-A resolution. PUBMED:9192620 EPMC:9192620
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Yang C, Curth U, Urbanke C, Kang C; , Nat Struct Biol 1997;4:153-157.: Crystal structure of human mitochondrial single-stranded DNA binding protein at 2.4 A resolution. PUBMED:9033597 EPMC:9033597
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Webster G, Genschel J, Curth U, Urbanke C, Kang C, Hilgenfeld R; , FEBS Lett 1997;411:313-316.: A common core for binding single-stranded DNA: structural comparison of the single-stranded DNA-binding proteins (SSB) from E. coli and human mitochondria. PUBMED:9271227 EPMC:9271227
Internal database links
SCOOP: | DUF3217 Phage_SSB tRNA_anti-codon tRNA_anti_2 |
Similarity to PfamA using HHSearch: | tRNA_anti-codon |
External database links
HOMSTRAD: | SSB |
PROSITE: | PDOC00602 |
SCOP: | 1kaw |
Transporter classification: | 3.A.7 |
This tab holds annotation information from the InterPro database.
InterPro entry IPR000424
The Escherichia coli single-strand binding protein [PUBMED:2087220] (gene ssb), also known as the helix-destabilising protein, is a protein of 177 amino acids. It binds tightly, as a homotetramer, to single-stranded DNA (ss-DNA) and plays an important role in DNA replication, recombination and repair. Closely related variants of SSB are encoded in the genome of a variety of large self-transmissible plasmids. SSB has also been characterized in bacteria such as Proteus mirabilis or Serratia marcescens. Eukaryotic mitochondrial proteins that bind ss-DNA and are probably involved in mitochondrial DNA replication are structurally and evolutionary related to prokaryotic SSB.
Primosomal replication protein N (PriB) is a specialist protein from bacteria that binds single-stranded DNA at the primosome assembly site (PAS). The primosome is a mobile multiprotein replication priming complex which is believe to operate on the lagging-strand template at the E. coli DNA replication fork [PUBMED:1856227]. The primosome consists of one monomer of PriC and DnaT, two monomers of PriA, two dimers of PriB and one hexamer of DnaB [PUBMED:8663106].
Gene Ontology
The mapping between Pfam and Gene Ontology is provided by InterPro. If you use this data please cite InterPro.
Molecular function | single-stranded DNA binding (GO:0003697) |
Domain organisation
Below is a listing of the unique domain organisations or architectures in which this domain is found. More...
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Pfam Clan
This family is a member of clan OB (CL0021), which has the following description:
The OB (oligonucleotide/oligosaccharide binding) was defined by Murzin [1]. The common part of the OB-fold, has a five-stranded beta-sheet coiled to form a closed beta-barrel. This barrel is capped by an alpha-helix located between the third and fourth strands [1].
The clan contains the following 110 members:
BOF BRCA-2_OB1 BRCA-2_OB3 CcmE CDC13_N Cdc13_OB2 CDC24_OB1 CDC24_OB2 CDC24_OB3 CSD CSD2 CusF_Ec CysA_C_terminal DNA_ligase_A_C DNA_ligase_C DNA_ligase_OB DNA_ligase_OB_2 DNA_pol_D_N DUF1344 DUF1449 DUF2110 DUF223 DUF2815 DUF3127 DUF3217 DUF3299 DUF4539 DUF5666 DUF961 EFP eIF-1a eIF-5a Elong-fact-P_C EutN_CcmL EXOSC1 FbpC_C_terminal Fimbrial_PilY2 GlcV_C_terminal Gp138_N gp32 Gp5_OB HIN ID MCM_OB mRNA_cap_C MRP-S35 NfeD NigD_N NlpE_C OB_aCoA_assoc OB_Dis3 OB_MalK OB_NTP_bind OB_RNB PCB_OB Phage_base_V Phage_DNA_bind Phage_SSB Pol_alpha_B_N POT1 POT1PC Prot_ATP_ID_OB Prot_ATP_OB_N RecG_wedge RecJ_OB RecO_N RecO_N_2 Rep-A_N Rep_fac-A_3 Rep_fac-A_C REPA_OB_2 Rho_RNA_bind Ribosom_S12_S23 Ribosomal_L2 Ribosomal_S17 Ribosomal_S28e Ribosomal_S4e RMI1_C RMI1_N RMI2 RNA_pol_Rbc25 RNA_pol_Rpb8 RNA_pol_RpbG RNase_II_C_S1 RPA43_OB Rrp44_CSD1 Rrp44_S1 RsgA_N RuvA_N S1 S1-like S1_2 SfsA_N SSB ssDBP Stn1 TEBP_beta Ten1 Ten1_2 TOBE TOBE_2 TOBE_3 TPP1 TRAM TRAM_2 tRNA_anti-codon tRNA_anti-like tRNA_anti_2 tRNA_bind TTC5_OBAlignments
We store a range of different sequence alignments for families. As well as the seed alignment from which the family is built, we provide the full alignment, generated by searching the sequence database (reference proteomes) using the family HMM. We also generate alignments using four representative proteomes (RP) sets, the UniProtKB sequence database, the NCBI sequence database, and our metagenomics sequence database. More...
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We make a range of alignments for each Pfam-A family. You can see a description of each above. You can view these alignments in various ways but please note that some types of alignment are never generated while others may not be available for all families, most commonly because the alignments are too large to handle.
Seed (49) |
Full (15361) |
Representative proteomes | UniProt (68227) |
NCBI (82718) |
Meta (2774) |
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RP15 (2237) |
RP35 (7328) |
RP55 (14815) |
RP75 (25462) |
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PP/heatmap | 1 |
1Cannot generate PP/Heatmap alignments for seeds; no PP data available
Key:
available,
not generated,
— not available.
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We make all of our alignments available in Stockholm format. You can download them here as raw, plain text files or as gzip-compressed files.
Seed (49) |
Full (15361) |
Representative proteomes | UniProt (68227) |
NCBI (82718) |
Meta (2774) |
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---|---|---|---|---|---|---|---|---|---|
RP15 (2237) |
RP35 (7328) |
RP55 (14815) |
RP75 (25462) |
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Raw Stockholm | |||||||||
Gzipped |
You can also download a FASTA format file containing the full-length sequences for all sequences in the full alignment.
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's seed alignment. 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 alignment.
Note: You can also download the data file for the tree.
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: | Prosite & COG2965 |
Previous IDs: | none |
Type: | Domain |
Sequence Ontology: | SO:0000417 |
Author: |
Finn RD |
Number in seed: | 49 |
Number in full: | 15361 |
Average length of the domain: | 102.90 aa |
Average identity of full alignment: | 28 % |
Average coverage of the sequence by the domain: | 63.34 % |
HMM information
HMM build commands: |
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 47079205 -E 1000 --cpu 4 HMM pfamseq
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Model details: |
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Model length: | 104 | ||||||||||||
Family (HMM) version: | 26 | ||||||||||||
Download: | download the raw HMM for this family |
Species distribution
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Interactions
There is 1 interaction for this family. More...
SSBStructures
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 SSB domain has been found. There are 189 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 sequence.
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