Characterization of two M17 family members in Escherichia coli, Peptidase A and Peptidase B

Bhosale, Manoj and Pande, Samay and Kumar, Anujith and Kairamkonda, Subhash and Nandi, Dipankar (2010) Characterization of two M17 family members in Escherichia coli, Peptidase A and Peptidase B. In: Biochemical and Biophysical Research Communications, 395 (1). pp. 76-81. (In Press)

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Abstract

Escherichia coil encodes two aminopeptidases belonging to the M17 family: Peptidase A (PepA) and Peptidase B (PepB). To gain insights into their substrate specificities, PepA or PepB were overexpressed in Delta pepN, which shows greatly reduced activity against the majority of amino acid substrates. Overexpression of PepA or PepB increases catalytic activity of several aminopeptidase substrates and partially rescues growth of Delta pepN during nutritional downshift and hightemperature stress. Purified PepA and PepB display broad substratespecificity and Leu, Lys, Met and Gly are preferred substrates. However, distinct differences are observed between these two paralogs: PepA is more stable at high temperature whereas PepB displays broader substrate specificity as it cleaves Asp and insulin B chain peptide. Importantly, this strategy, i.e. overexpression of peptidases in Delta pepN and screening a panel of substrates for cleavage, can be used to rapidly identify peptidases with novel substrate specificities encoded in genomes of different organisms. (C) 2010 Elsevier Inc. All rights reserved.

Item Type:	Journal Article
Publication:	Biochemical and Biophysical Research Communications
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Keywords:	Aminopeptidase; Cellular proteolysis; Comparative biochemistry; M1 family peptidase; M17 family peptidase; Substrate specificity
Department/Centre:	Division of Biological Sciences > Biochemistry
Date Deposited:	26 May 2010 09:44
Last Modified:	19 Sep 2010 06:07
URI:	http://eprints.iisc.ac.in/id/eprint/28072

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