Characterization and role of Peptidase N from Salmonella enterica serovar Typhimurium

Kumar, Anujith and Nandi, Dipankar (2007) Characterization and role of Peptidase N from Salmonella enterica serovar Typhimurium. In: Biochemical and Biophysical Research Communications, 353 (3). pp. 706-712.

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Abstract

ATP-independent peptidases are important during the distal steps of cytosolic protein degradation. The contribution of a member of this group, Peptidase N (PepN) was studied in Salmonella enterica serovar Typhimurium (Salmonella typhimurium). The $\Delta$ pepN strain displays greatly reduced cleavage of 9 out of a total of 13 exopeptidase substrates, demonstrating a significant contribution of PepN to cytosolic aminopeptidase activity. The cleavage profile of purified S. typhimurium PepN is Arg>Ala>Thr, demonstrating broad specificity. Comparative biochemical studies with purified PepN from Escherichia coli and S. typhimurium revealed the latter to be distinct: S. typhimurium PepN cleaves Thr-AMC more efficiently and is less sensitive to inhibition by N-ethylmaleimide. Studies with $\Delta$ pepN and PepN overexpression demonstrated its importance for growth during nutritional downshift in combination with high temperature stress. In summary, S. typhimurium PepN contributes significantly to cytosolic aminopeptidase activity and its role is manifested under selected stress conditions.

Item Type:	Journal Article
Publication:	Biochemical and Biophysical Research Communications
Publisher:	Elsevier
Additional Information:	Copyright of this article belongs to Elsevier.
Keywords:	Cellular proteolysis;Aminopeptidase;M1 peptidase;Substrate specificity;Stress
Department/Centre:	Division of Biological Sciences > Biochemistry
Date Deposited:	23 Feb 2007
Last Modified:	19 Sep 2010 04:35
URI:	http://eprints.iisc.ac.in/id/eprint/9945

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