P domain
IPR002884
Definition
In eukaryotes, many essential secreted proteins and peptide hormones are excised from larger precursors by members of a class of calcium-dependent endoproteinases, the prohormone-proprotein convertases (PCs).The P (known as such because it is essential for proteolytic activity), or Homo B, domain of ~150 residues is a distinctive characteristic of members of the proprotein convertase family. The P/Homo B domain appears to be necessary to both fold and maintain the subtilisin-like active catalytic module and to regulate its specialized features of calcium and more acidic pH dependence [[cite:PMID:9636145], [cite:PMID:9556596], [cite:PMID:12794637], [cite:PMID:19654332]]. The core of the P/Homo B domain consists of a jelly roll-like fold with eight β-strands. Nonbonded interactions between the catalytic and P/Homo B domains provide additional structural stabilization of the catalytic domains, which alone appear to be thermodynamically unstable [[cite:PMID:12794637], [cite:PMID:19654332]]. Most of the PC family members contained the cognate integrin binding RGD sequence within the middle of the P domain PMID:10212221, which may be required for intracellular compartmentalization and maintenance of enzyme stability within the ER. The integrity of the RGD sequence of proprotein convertase PC1 is critical for its zymogen and C-terminal processing and for its cellular trafficking [[cite:PMID:9307023], [cite:PMID:10212221]]. The carboxy-terminal tail provides uniqueness to each PC family member being the least conserved region of all convertases PMID:10842308.
7 human proteins with this domain
Each is a reviewed human protein in the Seroatlas serome and a potential autoantibody target; this domain groups them into one antibody-relevant category. Every entry links to its own record.
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