. 2013 Jun 5;288(31):22798–22808. doi: 10.1074/jbc.M113.460295

TABLE 1.

Predicted exposure scores of residues in the N-terminal domain of subunit a mutated to cysteine and the growth phenotypes of the corresponding single cysteine-containing mutants of Vph1p

Mutant	Exposure score^a	Vma⁺ phenotype^b
MM112	−^c	−
Cys-less	−	+
Ser-26	0	+
Gln-40	2	+
Lys-47	7	+
Lys-82	6	+
Asp-87	6	+
Gln-140	0	+
Asp-167	6	+
Asn-172	6	+
Gly-181	3	+
Gly-189	0	+
Asp-194	7	+
Glu-219	7	+
Lys-226	7	+
Ala-235	0	+
Asp-257	6	+
Ser-265	6	+
Lys-304	6	+
Asp-344	6	+
Ala-347	7	+
Ala-358	6	+
Ile-362	7	+

^a Predicted solvent accessibility scores for residues in the N-terminal domain of Vph1p were calculated using the I-TASSER program. Scores ranged from 0 (least accessible) to 7 (most accessible).

^b The growth phenotype of each mutant was tested by comparing growth on YEPD plates buffered to pH 7.5 and 5.5. Yeast lacking a functional V-ATPase grow at pH 5.5 but not at pH 7.5. MM112, the background yeast strain, lacks both Vph1p and Stv1p and fails to grow at pH 7.5.

^c Plus sign indicates wild-type growth; minus sign indicates no growth.