Structural comparison of the Pichia pastoris alcohol oxidase genes

Abstract

In methylotrophic yeasts, alcohol oxidase is the first enzyme in the methanol‐utilization pathway. The genome of one such yeast, Pichia pastoris, contains two alcohol oxidase genes, AOX1 and AOX2. Sequence analysis indicated that each gene encodes a similar protein of 663 amino acids. The protein‐coding regions of the genes were 92% and 97% homologous at the nucleotide and predicted amino acid sequence levels, respectively. In contrast to homology observed within the protein‐coding portions of the AOX genes, no homology was found in either the 5′ or 3′ non‐coding regions. Although alcohol oxidase is found in peroxisomes of P. pastoris, the AOX amino acid sequences did not contain a peptide sequence similar to the peroxisomal transport sequence found at the C‐terminus of some peroxisomally located proteins in higher eukaryotes.