<i>ASD4</i> is involved in nitrogen assimilation.

<p>(A) Δ<i>asd4</i> mutant strains were grown for 10 days on minimal media (MM) containing 1% (w/v) glucose (GMM) and 10 mM of the indicated sole nitrogen sources. L-isomers were used throughout this study. (B) After 10 days, Δ<i>asd4</i> growth was not further attenuated on GMM containing low concentrations of ammonium as the sole nitrogen. (C) Strains were grown for 10 days on MM containing 10 mM L-glutamine as the sole carbon and nitrogen source. WT = wild type Guy11 isolate, Δ<i>asd4 ASD4GFP</i> = Δ<i>asd4</i> complementation strain expressing Asd4 fused to GFP. Bars are added as a visual aid to the plate images in (B) and (C) to demarcate colony size.