TCDB is operated by the Saier Lab Bioinformatics Group

9.B.51 The Uncharacterized DUF202/YidH (YidH) Family

Members of the YidH Family include YidH of E. coli which has 115 aas and 3 TMSs, the first TMS having a low level of hydrophobicity, the second, having a moderate level of hydrophobicity, and the third, having very hydrophobic character.  These traits appear to be characteristic of most members of this family.  The transmembrane α-helical nature of YidH has been established (Eichmann et al. 2014).  Members of this family are found in bacteria, archaea and eukaryotes.  In fungi, long homologues of ~ 350 aas have the 3 TMS DUF202 domain at its extreme C-terminus, and it has a pf02656 domain. 

VTC1 or PHM4 protein of Saccharomyces cerevisiae (9.B.51.1.6) has 129 aas and 3 TMSs.  This protein corresponds to the C-terminal domain of polyphosphate polymerase (TC# 4..E.1) (Gerasimaitė et al. 2014).  VTC proteins influence the vacuolar H+-ATPase (V-ATPase) as well as vacuolar H+ uptake. Like the V-ATPase V0 sector, VTCs are important factors in vacuolar membrane fusion (Müller et al. 2003). These proteins can be parts of the yeast (eukaryotic) Vacuolar (Acidocalcisome) Polyphosphate Polymerase (V-PPP) Family (TC# 4.E.1).

References associated with 9.B.51 family:

Eichmann, C., J. Orts, C. Tzitzilonis, B. Vögeli, S. Smrt, J. Lorieau, and R. Riek. (2014). Intermolecular detergent-membrane protein noes for the characterization of the dynamics of membrane protein-detergent complexes. J Phys Chem B 118: 14288-14301. 25419869
Gerasimaitė, R., S. Sharma, Y. Desfougères, A. Schmidt, and A. Mayer. (2014). Coupled synthesis and translocation restrains polyphosphate to acidocalcisome-like vacuoles and prevents its toxicity. J Cell Sci 127: 5093-5104. 25315834
Müller, O., H. Neumann, M.J. Bayer, and A. Mayer. (2003). Role of the Vtc proteins in V-ATPase stability and membrane trafficking. J Cell Sci 116: 1107-1115. 12584253