Patent ID: 7449308

Claim:
A method for producing a recombinant glycoprotein comprising complex or hybrid N-glycans in a yeast or filamentous fungus host cell that does not display a 1,6 mannosyltransferase activity, the method comprising the step of introducing into the host cell a nucleic acid encoding an alpha-1,2 mannosidase enzyme, the enzyme comprising: a) an alpha-1,2 mannosidase catalytic domain; fused to b) a cellular targeting signal peptide not normally associated with the catalytic domain and selected to target the enzyme to the ER or Golgi apparatus of the host cell where the enzyme functions optimally; whereby, upon passage of the recombinant glycoprotein through the ER or Golgi apparatus of the host cell, greater than 30 mole percent of the N-glycan structures attached thereto are converted to a Man 5 GlcNAc 2 glycoform that can serve as a substrate for additional glycosylation enzymes so that the glycoprotein comprising complex or hybrid N-glycans can be formed.