prolyl 4-hydroxylase subunit alpha-3 (4-PH alpha-3, procollagen-proline, 2-oxoglutarate-4-dioxygenase subunit alpha-3, P4HA3)

Function: - catalyzes the post-translational formation of 4- hydroxyproline in -Xaa-Pro-gly- sequences in collagens & other proteins procollagen L-proline + 2-oxoglutarate + O₂ procollagen trans-4-hydroxy-L-proline + succinate + CO₂ Cofactor: iron, ascorbate Structure: - heterotetramer of two alpha-3 chains & two beta chains (the beta chain is the multi-functional PDI) - N-glycosylation plays no role in the catalytic activity - belongs to the P4HA family - contains 1 PKHD (prolyl/lysyl hydroxylase) domain - contains 1 TPR repeat Compartment: endoplasmic reticulum lumen (probable) Alternative splicing: named isoforms=2 Expression: - highly expressed in placenta, liver & fetal skin - weakly expressed in fetal epiphyseal cartilage, fetal liver, fibroblast, lung & skeletal muscle Pathology: - expressed also in fibrous cap of carotid atherosclerotic lesions

General

dioxygenase glycoprotein

Properties

SIZE: entity length = 544 aa MW = 61 kD COMPARTMENT: endoplasmic reticulum MOTIF: signal sequence {1-19} coiled coil {107-131} tetratricopeptide repeat {227-260} MOTIF: N-glycosylation site {N242} PKHD {422-529} MOTIF: Iron [Fe]-binding site SITE: 440-440 Iron [Fe]-binding site SITE: 442-442 N-glycosylation site {N482} Iron [Fe]-binding site SITE: 510-510 lysine residue {K520}

Database Correlations

UniProt Q7Z4N8 PFAM correlations Kegg hsa:2832 ENZYME 1.14.11.2

References

UniProt :accession Q7Z4N8