Prolyl-4-Hydroxylase Alpha Polypeptide I (P4Ha1)

P4HA1 is a component of prolyl 4-hydroxylase, a key enzyme in collagen synthesis composed of two identical alpha subunits and two beta subunits. The encoded protein is one of several different types of alpha subunits and provides the major part of the catalytic site of the active enzyme. In collagen and related proteins, prolyl 4-hydroxylase catalyzes the formation of 4-hydroxyproline that is essential to the proper three-dimensional folding of newly synthesized procollagen chains. Alternatively spliced transcript variants encoding different isoforms have been described.

Prolyl 4-hydroxylase plays a central role in collagen synthesis. It catalyzes the formation of 4-hydroxyproline in collagens by hydroxylation of proline residues in peptide linkages.