Targeted disruption of the kstD gene encoding a 3-ketosteroid delta(1)-dehydrogenase isoenzyme of Rhodococcus erythropolis strain SQ1.

ABSTRACT: Microbial phytosterol degradation is accompanied by the formation of steroid pathway intermediates, which are potential precursors in the synthesis of bioactive steroids. Degradation of these steroid intermediates is initiated by Delta(1)-dehydrogenation of the steroid ring structure. Characterization of a 2.9-kb DNA fragment of Rhodococcus erythropolis SQ1 revealed an open reading frame (kstD) showing similarity with known 3-ketosteroid Delta(1)-dehydrogenase genes. Heterologous expression of kstD yielded 3-ketosteroid Delta(1)-dehydrogenase (KSTD) activity under the control of the lac promoter in Escherichia coli. Targeted disruption of the kstD gene in R. erythropolis SQ1 was achieved, resulting in loss of more than 99% of the KSTD activity. However, growth on the steroid substrate 4-an

SUBMITTER: van Der Geize R 

PROVIDER: S-EPMC101450 | biostudies-literature | 2000 May

REPOSITORIES: biostudies-literature