Abstract
Complementation of an E. coli mutant auxotrophic for the branched-chain amino acids (BCAA)—valine, leucine, and isoleucine—by the ilvG gene (slr2088) of the cyanobacterium Synechocystis PCC6803 indicates that this gene encodes an active α-acetohydroxy acid synthase. Differences of response of the recombinants to the addition of the essential amino acids suggested a lower specificity for the initial reaction of the valine/leucine chain than for the isoleucine one. Inactivation of ilvG in Synechocystis led to a leaky phenotype, suggesting a capacity to compensate the auxotrophies by other processes. This observation is discussed in view of the general difficulty of obtaining auxotrophs in cyanobacteria.
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Received: 16 October 2001 / Accepted: 26 November 2001
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Kouhen, OE., Joset, F. Biosynthesis of the Branched-Chain Amino Acids in the Cyanobacterium Synechocystis PCC6803: Existence of Compensatory Pathways. Curr Microbiol 45, 94–98 (2002). https://doi.org/10.1007/s00284-001-0097-2
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DOI: https://doi.org/10.1007/s00284-001-0097-2