Crystal Structure of Murein-Tripeptide Amidase MpaA from Escherichia coli O157 at 2.6 Å Resolution

Title:Crystal Structure of Murein-Tripeptide Amidase MpaA from Escherichia coli O157 at 2.6 Å Resolution

Volume: 24 Issue: 2

Author(s): Yinliang Ma, Guohui Bai, Yaqi Cui, Jing Zhao, Zenglin Yuan and Xiuhua Liu

Affiliation:

Keywords: PG, Mtp, E. coli O157, mtp amidase, MpaA, crystal structure.

Abstract: Peptidoglycan (PG) is an essential component of the cell wall, and undergoes reconstruction by various PG hydrolases during cell growth, development and division. The murein- tripeptide (Mtp) amidase MpaA belongs to PG hydrolase family and is responsible for cleaving the γ-D-Glumeso- Dap amide bond in the Mtp released during PG turnover. The current paper reports the crystal structure of MpaA from Escherichia coli (E. coli) O157 at 2.6 Å resolution. The asymmetric unit consists of two protein molecules and each monomer represents the common α/β fold of metallocarboxypeptidases (MCP). The Tyr¹³³-Asp¹⁴³ loop appears to mediate the entrance and binding of the substrate into the active groove. A structural comparison of MpaA with its homologue from Vibrio harveyi showed that MpaA has narrower active pocket entrance with a smaller surface opening, which is determined by the Val²⁰⁴-Thr²¹¹ loop. The reported structure provides a starting point for the molecular mechanism of MpaA in a significant human pathogen.

Cite this article as:

Ma Yinliang, Bai Guohui, Cui Yaqi, Zhao Jing, Yuan Zenglin and Liu Xiuhua, Crystal Structure of Murein-Tripeptide Amidase MpaA from Escherichia coli O157 at 2.6 Å Resolution, Protein & Peptide Letters 2017; 24 (2) . https://dx.doi.org/10.2174/0929866523666161128153128