Summary: Phage portal protein
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Phage portal protein Provide feedback
Bacteriophage portal proteins form a dodecamer and is located at a five-fold vertex of the viral capsid. The portal complex forms a channel through which the viral DNA is packaged into the capsid, and exits during infection. The portal protein is though to rotate during DNA packaging . Portal proteins from different phage show little sequence homology, so this family does not represent all portal proteins.
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This tab holds annotation information from the InterPro database.
InterPro entry IPR006944
This is a family of bacteriophage, prophage and Gene Transfer Agent (GTA) portal proteins. Positioned at one of the twelve icosahedral vertices, of the viral capsid, is a dodecameric complex of the virus encoded portal protein. This dodecameric complex, known as the portal or connector complex, forms the channel through which the viral DNA is packaged into the capsid, and through which it exits during infection. While the portal proteins from different phage show relatively little sequence homology and vary widely in molecular weight, portal complexes display significant morphological similarity as determined by electron microscopy. Morphologically, they present as disk-like structures approximately 150 Angstroms in diameter with radially arranged projections and a 30 Angstroms central channel. The packaging reaction is energy dependent and typically involves several components. ATP hydrolysis provides the driving force, and it is estimated that one ATP molecule is required for every base pair that is packaged. It appears that the portal motor may represent a new and extremely powerful class of motor which couples rotation to DNA translocation [PUBMED:11839289].
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Curation and family details
|Seed source:||Pfam-B_6050 (release 7.6)|
|Number in seed:||127|
|Number in full:||3192|
|Average length of the domain:||315.20 aa|
|Average identity of full alignment:||19 %|
|Average coverage of the sequence by the domain:||80.95 %|
|HMM build commands:||
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 23193494 -E 1000 --cpu 4 HMM pfamseq
|Family (HMM) version:||7|
|Download:||download the raw HMM for this family|
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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 Phage_portal domain has been found. There are 3 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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