The M-Pol I and M-Pol II complexes possess alpha-1,6-mannosyltransferase activity and are probably involved in the elongation of the mannan backbone of N-linked glycans on cell wall and periplasmic proteins. May also provide alpha-1,2-mannosyltransferase activity to the M-Pol I complex. Protein modification; protein glycosylation. The M-Pol I complex contains MNN9 and VAN1. The M-Pol II complex is composed of ANP1, MNN9, MNN10, MNN11 and HOC1. Cis-Golgi (PubMed:9430634). Recycles between endoplasmic reticulum and Golgi (PubMed:11095735). Present with 1630 molecules/cell in log phase SD medium. Belongs to the ANP1/MMN9/VAN1 family.