Sequence and structure comparison suggest that methionine aminopeptidase, prolidase, aminopeptidase P, and creatinase share a common fold

Proc Natl Acad Sci U S A. 1994 Mar 29;91(7):2473-7. doi: 10.1073/pnas.91.7.2473.


Amino acid sequence comparison suggests that the structure of Escherichia coli methionine aminopeptidase (EC and the C-terminal domain of Pseudomonas putida creatinase (EC are related. A detailed comparison of the three-dimensional folds of the two enzymes confirms this homology: with an approximately 260-residue chain segment, 218 C alpha atoms of the structures superimpose within 2.5 A; only 41 of these overlapping positions (i.e., 19%) feature identical amino acids in the two protein chains. Notwithstanding this striking correspondence in structure, methionine aminopeptidase binds and is stimulated by Co2+, while creatinase is not a metal-dependent enzyme. Searches of protein data banks using sequence and structure-based profiles reveal other enzymes, including aminopeptidase P (EC, prolidase (EC, and agropine synthase, that likely share the same "pita-bread" fold common to creatinase and methionine aminopeptidase.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Aminopeptidases / chemistry*
  • Dipeptidases / chemistry*
  • Escherichia coli / enzymology
  • Methionyl Aminopeptidases
  • Models, Molecular
  • Molecular Sequence Data
  • Protein Conformation*
  • Pseudomonas putida / enzymology
  • Sequence Homology, Amino Acid
  • Ureohydrolases / chemistry*


  • Aminopeptidases
  • Methionyl Aminopeptidases
  • X-Pro aminopeptidase
  • Dipeptidases
  • proline dipeptidase
  • Ureohydrolases
  • creatinase