9.B.235.  The Mitochondrial Outer Membrane Protein-14 (Om14) Family  

Proteomics on the outer membrane from yeast mitochondria suggest that most of these mitochondrial proteins have α-helical TMSs. These proteins are usually predicted to have a single α-helical TMS at either the N- or C-terminus, but more complex topologies are also seen. Burri et al. 2006 purified Om14 and found that it probably has 3 TMSs. It is encoded by the gene, YBR230c. Levels of the Om14 protein are much lower in cells grown on glucose than in cells grown on nonfermentable carbon sources. The α-helical outer membrane proteins presumably provide functions derived after the endosymbiotic event and require the translocase in the outer mitochondrial membrane complex (TC# 3.A.8) for membrane  insertion (Burri et al. 2006).



Burri, L., K. Vascotto, I.E. Gentle, N.C. Chan, T. Beilharz, D.I. Stapleton, L. Ramage, and T. Lithgow. (2006). Integral membrane proteins in the mitochondrial outer membrane of Saccharomyces cerevisiae. FEBS J. 273: 1507-1515.


TC#NameOrganismal TypeExample

Functionally uncharacterized mitochondrial outer membrane protein, Om14, of 134 aas and 3 TMSs (Burri et al. 2006).

Om14 of Saccharomyces cerevisiae


Om14 of 160 aas and 3 TMSs.

Om14 of Lachancea thermotolerans (Yeast) (Kluyveromyces thermotolerans)


Om14 of 173 aas and 3 TMSs.

Om14 of Kluyveromyces marxianus


Om14 of 189 aas and 3 TMSs.

Om14 of Cyberlindnera fabianii


Om14 of 178 aas and 3 TMSs.

Om14 of Hyphopichia burtonii


Om14 of 182 aas and 3 TMSs.

Om14 of Pichia sorbitophila (Hybrid yeast)


Om14 of 152 aas and 3 TMSs.

Om14 of Yarrowia lipolytica (Yeast) (Candida lipolytica)


Om14 of 176 aas and 2 TMSs.

Om14 of Talaromyces stipitatus (Penicillium stipitatum)


Uncharacterized protein of 180 aas and 2 or 3 C-terminal TMSs.

UP of Malassezia pachydermatis


TC#NameOrganismal TypeExample