The present invention provides a
pipecolic acid 4-hydroxylase
protein exemplified by the following (A), (B), and (C), having activity to react with L-
pipecolic acid in the presence of 2-oxoglutaric acid and iron(II) ions to produce trans-4-hydroxy-L-
pipecolic acid, and a method for producing 4-hydroxy
amino acid, which method comprises reacting the pipecolic acid 4-hydroxylase
protein, cells containing the
protein, a treated product of the cells, and / or a culture liquid obtained by culturing the cells, with α-
amino acid to produce 4-hydroxy
amino acid:(A) a polypeptide comprising the amino acid sequence represented by SEQ ID NO:2, 4, 6, 8, 10, 12, 16, or 18;(B) a polypeptide comprising the amino acid sequence represented by SEQ ID NO:2, 4, 6, 8, 10, 12, 16, or 18 except that one or several amino acids are deleted, substituted, and / or added, and having pipecolic acid 4-hydroxylase activity; and(C) a polypeptide having an amino acid sequence that is not less than 80% identical to the amino acid sequence represented by SEQ ID NO:2, 4, 6, 8, 10, 12, 16, or 18, and having pipecolic acid 4-hydroxylase activity.