MOLECULAR-CLONING AND NUCLEOTIDE-SEQUENCE OF THE GENOMIC DNA FOR 1,2-ALPHA-D-MANNOSIDASE GENE, MSDC FROM PENICILLIUM-CITRINUM

A gene encoding 1,2-alpha-D-mannosidase (EC 3.2.1.113) was cloned from Penicillium citrinum genomic DNA using the polymerase chain reaction (PCR). The coding region of the gene, msdC, occupied 1737 bp and was s eparated into four exons by three introns. The predicted protein consi sted of 511 amino acid residues with M(r) 56 569. Penicillium enzyme h ad a hydrophobic signal peptide at the N-terminal region as did mammal ian membrane-bound alpha-mannosidases, but in this case a proteolytic cleavage occurred at Lys-35-Ser-36 to remove the signal sequence durin g cell growth. Parts of amino acid sequences were similar to those of mammalian Golgi alpha-mannosidase IA and IB, but the sequence around t he aspartic acid residue which interacted with 1-deoxymannojinimycin ( Yoshida et al. (1994) Biochem. J. 303, 97-103) was unique in Penicilli um enzyme.