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Structure and mechanism of a proline-specific aminopeptidase from Escherichia coli

Journal Article


Abstract


  • The structure of the proline-specific amino-peptidase (EC 3.4.11.9) from Escherichia coli has been solved and refined for crystals of the native enzyme at a 2.0-Å resolution, for a dipeptide-inhibited complex at 2.3-Å resolution, and for a low-pH inactive form at 2.7-Å resolution. The protein crystallizes as a tetramer, more correctly a dimer of dimers, at both high and low pH, consistent with observations from analytical ultracentrifuge studies that show that the protein is a tetramer under physiological conditions. The monomer folds into two domains. The active site, in the larger C-terminal domain, contains a dinuclear manganese center in which a bridging water molecule or hydroxide ion appears poised to act as the nucleophile in the attack on the scissile peptide bond of Xaa-Pro. The metal- binding residues are located in a single subunit, but the residues surrounding the active site are contributed by three subunits. The fold of the protein resembles that of creatine amidinohydrolase (creatinase, not a metalloenzyme). The C-terminal catalytic domain is also similar to the single-domain enzyme methionine aminopeptidase that has a dinuclear cobalt center.

Publication Date


  • 1998

Citation


  • Wilce, M. C. J., Bond, C. S., Dixon, N. E., Freeman, H. C., Guss, J. M., Lilley, P. E., & Wilce, J. A. (1998). Structure and mechanism of a proline-specific aminopeptidase from Escherichia coli. Proceedings of the National Academy of Sciences of the United States of America, 95(7), 3472-3477. doi:10.1073/pnas.95.7.3472

Scopus Eid


  • 2-s2.0-0032584215

Start Page


  • 3472

End Page


  • 3477

Volume


  • 95

Issue


  • 7

Abstract


  • The structure of the proline-specific amino-peptidase (EC 3.4.11.9) from Escherichia coli has been solved and refined for crystals of the native enzyme at a 2.0-Å resolution, for a dipeptide-inhibited complex at 2.3-Å resolution, and for a low-pH inactive form at 2.7-Å resolution. The protein crystallizes as a tetramer, more correctly a dimer of dimers, at both high and low pH, consistent with observations from analytical ultracentrifuge studies that show that the protein is a tetramer under physiological conditions. The monomer folds into two domains. The active site, in the larger C-terminal domain, contains a dinuclear manganese center in which a bridging water molecule or hydroxide ion appears poised to act as the nucleophile in the attack on the scissile peptide bond of Xaa-Pro. The metal- binding residues are located in a single subunit, but the residues surrounding the active site are contributed by three subunits. The fold of the protein resembles that of creatine amidinohydrolase (creatinase, not a metalloenzyme). The C-terminal catalytic domain is also similar to the single-domain enzyme methionine aminopeptidase that has a dinuclear cobalt center.

Publication Date


  • 1998

Citation


  • Wilce, M. C. J., Bond, C. S., Dixon, N. E., Freeman, H. C., Guss, J. M., Lilley, P. E., & Wilce, J. A. (1998). Structure and mechanism of a proline-specific aminopeptidase from Escherichia coli. Proceedings of the National Academy of Sciences of the United States of America, 95(7), 3472-3477. doi:10.1073/pnas.95.7.3472

Scopus Eid


  • 2-s2.0-0032584215

Start Page


  • 3472

End Page


  • 3477

Volume


  • 95

Issue


  • 7