Disease relevance of beta-lysine

• Mutants of Escherichia coli were generated in which residue beta-lysine 155, at the end of the above sequence, was replaced by glutamine or glutamate [1].
• Metabolism of L-beta-lysine by a Pseudomonas. Purification and properties of a deacetylase-thiolesterase utilizing 4-acetamidobutyryl CoA and related compounds [2].
• Interestingly, the selective toxicity of ST-D possessing 3x beta-lysine moiety was altered from broad-spectrum to bacteria-specific by the hydrolysis of streptolidine lactam, although ST-F (1 x beta-lysine) was detoxified by SttH in both prokaryotes and eukaryotes (yeasts) [3].
• We show that the nourseothricin-producing Streptomyces noursei contains an enzyme (NpsA) of an apparent M(r) 56,000 that specifically activates beta-lysine by adenylation but does not bind to it as a thioester [4].

High impact information on beta-lysine

• Moreover, the conformations of the beta-lysine-related radicals at the active sites of E. coli and clostridial LAM are different [5].
• A beta-lysine adenylating enzyme and a beta-lysine binding protein involved in poly beta-lysine chain assembly in nourseothricin synthesis in Streptomyces noursei [4].
• Racemomycin-B (RM-B), the main component of Streptomyces lavendulae OP-2 which is the basis of 50% of the antibiotics produced, is a streptothricin antibiotic which contains three beta-lysine moieties in the molecule [6].
• The resistance of E. coli strains to the antibiotic nourseothricin is known to be caused by an acetyltransferase acetylating the beta-lysine chain of the antibiotic [7].

Biological context of beta-lysine

• The presence of one single adenylating beta-lysine activating enzyme in nourseothricin-producing streptomycete and a separate binding protein suggests an iteratively operating NRPS-module catalyses synthesis of the poly beta-lysine chain [4].

References