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Publication Abstract from PubMed

Protein degradation by aminopeptidases is involved in bacterial responses to stress. Escherichia coli produces two metal-dependent M17 family leucine aminopeptidases (LAPs), aminopeptidase A (PepA) and aminopeptidase B (PepB). Several structures have been solved for PepA as well as other bacterial M17 peptidases. Herein, we report the first structures of a PepB M17 peptidase. The E. coli PepB protein structure was determined at a resolution of 2.05 and 2.6 A. One structure has both Zn(2+) and Mn(2+) , while the second structure has two Zn(2+) ions bound to the active site. A 2.75 A apo structure is also reported for PepB from Yersinia pestis. Both proteins form homohexamers, similar to the overall arrangement of PepA and other M17 peptidases. However, the divergent N-terminal domain in PepB is much larger resulting in a tertiary structure that is more expanded. Modeling of a dipeptide substrate into the C-terminal LAP domain reveals contacts that account for PepB to uniquely cleave after aspartate.

Comparison of metal-bound and unbound structures of aminopeptidase B proteins from Escherichia coli and Yersinia pestis.,Minasov G, Lam MR, Rosas-Lemus M, Slawek J, Woinska M, Shabalin IG, Shuvalova L, Palsson BO, Godzik A, Minor W, Satchell KJF Protein Sci. 2020 Jul;29(7):1618-1628. doi: 10.1002/pro.3876. Epub 2020 May 8. PMID:32306515^[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.