Figure 3.

CBS variant growth rates at various levels of exogenous cofactor supplementation. (A) Growth rates for six variants grown with four levels of pyridoxine supplementation (400, 4, 2, and 1 ng/mL) in HEM1 yeast strains. Growth rates are expressed relative to yeast with the major human CBS allele grown with the same media conditions. (B) Growth rates for five of the same variants grown in hem1Δ strains, in either a high level of pyridoxine (400 ng/mL, left panel) or a low level of pyridoxine (2 ng/mL, right). Additionally, these strains were grown with either high δ-ALA supplementation (50 μg/mL) or low δ-ALA supplementation (5 μg/mL). The K267M variant was omitted because it did not show any sensitivity to pyridoxine levels (A). All error bars indicate the standard deviation of at least three independent transformants.