Growth, Enzyme Levels, and Some Metabolic Properties of an Escherichia coli Mutant Grown on l -Threonine as the Sole Carbon Source

CONTENT ALERTS Receive: RSS Feeds, eTOCs, free email alerts (when new articles cite this article), more» Information about commercial reprint orders: http://jb.asm.org/site/misc/reprints.xhtml To subscribe to to another ASM Journal go to: http://journals.asm.org/site/subscriptions/ Downloaded from http://jb.asm.org/ on December 7, 2011 by deepdyve AUTHORS' CORRECTION SHARON A. BOYLAN AND EUGENE E. DEKKER Department of Biological Chemistry, The University of Michigan, Ann Arbor, Michigan 48109 Volume 156, no. 1, p. 273-280: In the studies reported in this paper, we used a mutant strain of E. coli K-12 that was obtained by forcing wild-type cells to grow on L-threonine as the sole carbon source. This mutant strain has constitutively derepressed levels of L-threonine dehydrogenase; we reported previously its isolation and use to obtain pure enzyme (Biochem. Biophys. Res. Commun. 85:190-197, 1978). It should be noted that a derived strain of E. coli K-12 that uses threonine as the sole source of carbon and energy has also been isolated by Chan and Newman (T. T. K. Chan and E. B. Newman, J. Bacteriol. 145:1150-1153, 1981). The authors and the editor regret omission of this citation. Whereas in their studies Chan and Newman used cell suspensions to observe qualitatively an accumulation of glycine in the medium, we used cell extracts to determine a quantitative conversion of threonine to glycine. Chan and Newman also reported the presence of 2amino-3-ketobutyrate ligase activity in extracts of their derived mutant strain; we determined that for our mutant cells this ligase activity exceeds the level found in wild-type cells by at...