lysC

{{Short description|Bacterial enzyme}}

{{about||the protease|Endoproteinase Lys-C|the Drosophila protein|Lysozyme}}

LysC is a prokaryotic aspartokinase involved in the biosynthesis of the amino acid lysine. It is found in a variety of bacteria, including Bacillus subtilis, Escherichia coli and Corynebacterium glutamicum.{{cite journal|last1=Grundy|first1=F. J.|last2=Lehman|first2=S. C.|last3=Henkin|first3=T. M.|title=The L box regulon: Lysine sensing by leader RNAs of bacterial lysine biosynthesis genes|journal=Proceedings of the National Academy of Sciences|date=1 October 2003|volume=100|issue=21|pages=12057–12062|doi=10.1073/pnas.2133705100|pmid=14523230|pmc=218712|bibcode=2003PNAS..10012057G|doi-access=free}} It is notable for containing a riboswitch, a structure in its messenger RNA that prevents its translation when bound to lysine.{{cite journal|last1=Sudarsan|first1=N.|title=An mRNA structure in bacteria that controls gene expression by binding lysine|journal=Genes & Development|date=16 October 2003|volume=17|issue=21|pages=2688–2697|doi=10.1101/gad.1140003|pmid=14597663|pmc=280618}} Such lysine riboswitch thus acts as a mechanism of negative feedback.