Summary: Microsomal signal peptidase 12 kDa subunit (SPC12)
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Microsomal signal peptidase 12 kDa subunit (SPC12) Provide feedback
This family consists of several microsomal signal peptidase 12 kDa subunit proteins. Translocation of polypeptide chains across the endoplasmic reticulum (ER) membrane is triggered by signal sequences. Subsequently, signal recognition particle interacts with its membrane receptor and the ribosome-bound nascent chain is targeted to the ER where it is transferred into a protein-conducting channel. At some point, a second signal sequence recognition event takes place in the membrane and translocation of the nascent chain through the membrane occurs. The signal sequence of most secretory and membrane proteins is cleaved off at this stage. Cleavage occurs by the signal peptidase complex (SPC) as soon as the lumenal domain of the translocating polypeptide is large enough to expose its cleavage site to the enzyme. The signal peptidase complex is possibly also involved in proteolytic events in the ER membrane other than the processing of the signal sequence, for example the further digestion of the cleaved signal peptide or the degradation of membrane proteins. Mammalian signal peptidase is as a complex of five different polypeptide chains. This family represents the 12 kDa subunit (SPC12).
Literature references
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Kalies KU, Hartmann E; , J Biol Chem 1996;271:3925-3929.: Membrane topology of the 12- and the 25-kDa subunits of the mammalian signal peptidase complex. PUBMED:8632014 EPMC:8632014
This tab holds annotation information from the InterPro database.
InterPro entry IPR009542
This family consists of several microsomal signal peptidase 12kDa subunit proteins. Translocation of polypeptide chains across the endoplasmic reticulum (ER) membrane is triggered by signal sequences. Subsequently, signal recognition particle interacts with its membrane receptor and the ribosome-bound nascent chain is targeted to the ER where it is transferred into a protein-conducting channel. At some point, a second signal sequence recognition event takes place in the membrane and translocation of the nascent chain through the membrane occurs. The signal sequence of most secretory and membrane proteins is cleaved off at this stage. Cleavage occurs by the signal peptidase complex (SPC) as soon as the lumenal domain of the translocating polypeptide is large enough to expose its cleavage site to the enzyme. The signal peptidase complex is possibly also involved in proteolytic events in the ER membrane other than the processing of the signal sequence, for example the further digestion of the cleaved signal peptide or the degradation of membrane proteins. Mammalian signal peptidase is as a complex of five different polypeptide chains. This family represents the 12kDa subunit (SPC12) [PUBMED:8632014].
Gene Ontology
The mapping between Pfam and Gene Ontology is provided by InterPro. If you use this data please cite InterPro.
Cellular component | integral component of membrane (GO:0016021) |
signal peptidase complex (GO:0005787) | |
Molecular function | peptidase activity (GO:0008233) |
Biological process | signal peptide processing (GO:0006465) |
Domain organisation
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Alignments
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 (135) |
Full (1280) |
Representative proteomes | UniProt (2016) |
NCBI (2251) |
Meta (3) |
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RP15 (106) |
RP35 (364) |
RP55 (594) |
RP75 (857) |
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PP/heatmap | 1 |
1Cannot generate PP/Heatmap alignments for seeds; no PP data available
Key:
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Seed (135) |
Full (1280) |
Representative proteomes | UniProt (2016) |
NCBI (2251) |
Meta (3) |
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RP15 (106) |
RP35 (364) |
RP55 (594) |
RP75 (857) |
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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: | Pfam-B_21331 (release 10.0) |
Previous IDs: | none |
Type: | Family |
Sequence Ontology: | SO:0100021 |
Author: |
Moxon SJ |
Number in seed: | 135 |
Number in full: | 1280 |
Average length of the domain: | 68.70 aa |
Average identity of full alignment: | 35 % |
Average coverage of the sequence by the domain: | 60.03 % |
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: | 71 | ||||||||||||
Family (HMM) version: | 14 | ||||||||||||
Download: | download the raw HMM for this family |
Species distribution
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