Leucyl aminopeptidase PepA

Colloms, S. D. (2004) Leucyl aminopeptidase PepA. In: Barrett, A.J., Woessner, J.F. and Rawlings, N.D. (eds.) Handbook of Proteolytic Enzymes [2nd ed.]. Volume 1: Aspartic and Metallo Peptidases. Elsevier, pp. 905-910. ISBN 9780120796113 (doi: 10.1016/B978-0-12-079611-3.50277-9)

Abstract

This chapter examines the structural chemistry and the biological aspects of Leucyl aminopeptidase PepA. A heat-stable aminopeptidase with similar biochemical properties to eukaryotic leucine aminopeptidase was purified to homogeneity from Escherichia coli K-12 by Vogt and named aminopeptidase I. The bacterial leucyi aminopeptidases range from 491 to 524 amino acids in length. E. coli PepA has 503 amino acids with a predicted Mr of 54,879. The enzyme in solution has an MT of 323,000, consistent with a hexameric structure. Alignment of E. coli PepA with bovine lens leucyi aminopeptidase reveals 44% sequence identity in the catalytic C-terminal domain, but only 18% identity in the N-terminal domain. Within the bacterial leucyi aminopeptidases, there is also more sequence similarity between catalytic C-terminal domains than between N-terminal domains. PepA is one of three broad-range aminopeptidases, with overlapping substrate specificity in E. coli and S. typhimurium. These three aminopeptidases, together with the dipeptidase PepD, can hydrolyze a variety of peptides supplied in the growth medium, allowing their use as amino acid sources. PepA also cleaves and activates several peptide toxins. PepA is one of two peptidases in S. typhimurium capable of activating albomycin, though albomycin is not cleaved by E. coli PepA.

• Item Type: Book Sections
• Status: Published
• Glasgow Author(s) Enlighten ID: Colloms, Dr Sean
• Authors: Colloms, S. D.
• College/School: College of Medical Veterinary and Life Sciences > School of Molecular Biosciences
• Publisher: Elsevier
• ISBN: 9780120796113