PLOD1 encode a polypeptide of 709 amino acid residues and a signal peptide of 18 amino acids. The human coding sequence shows 72% identity to the chick sequences at the nucleotide level and 76% identity at the amino acid level. The C-terminal region is especially well conserved; residues 588 to 727 show 94% identity between the 2 species and residues 639 to 715 show 99% identity. The gene for lysyl hydroxylase, symbolized PLOD (for procollagen-lysine, 2-oxoglutarate 5-dioxygenase), was mapped to chromosome 1 by Southern blot analysis of human/mouse somatic cell hybrids, to the 1pter-1p34 region by use of cell hybrids that contained various rearrangements of human chromosome 1, and to 1p36.3-p36.2 by in situ hybridization.