Back to Search
Start Over
Crystal structures and enzymatic properties of three formyltransferases from archaea: environmental adaptation and evolutionary relationship.
- Source :
-
Protein science : a publication of the Protein Society [Protein Sci] 2002 Sep; Vol. 11 (9), pp. 2168-78. - Publication Year :
- 2002
-
Abstract
- Formyltransferase catalyzes the reversible formation of formylmethanofuran from N(5)-formyltetrahydromethanopterin and methanofuran, a reaction involved in the C1 metabolism of methanogenic and sulfate-reducing archaea. The crystal structure of the homotetrameric enzyme from Methanopyrus kandleri (growth temperature optimum 98 degrees C) has recently been solved at 1.65 A resolution. We report here the crystal structures of the formyltransferase from Methanosarcina barkeri (growth temperature optimum 37 degrees C) and from Archaeoglobus fulgidus (growth temperature optimum 83 degrees C) at 1.9 A and 2.0 A resolution, respectively. Comparison of the structures of the three enzymes revealed very similar folds. The most striking difference found was the negative surface charge, which was -32 for the M. kandleri enzyme, only -8 for the M. barkeri enzyme, and -11 for the A. fulgidus enzyme. The hydrophobic surface fraction was 50% for the M. kandleri enzyme, 56% for the M. barkeri enzyme, and 57% for the A. fulgidus enzyme. These differences most likely reflect the adaptation of the enzyme to different cytoplasmic concentrations of potassium cyclic 2,3-diphosphoglycerate, which are very high in M. kandleri (>1 M) and relatively low in M. barkeri and A. fulgidus. Formyltransferase is in a monomer/dimer/tetramer equilibrium that is dependent on the salt concentration. Only the dimers and tetramers are active, and only the tetramers are thermostable. The enzyme from M. kandleri is a tetramer, which is active and thermostable only at high concentrations of potassium phosphate (>1 M) or potassium cyclic 2,3-diphosphoglycerate. Conversely, the enzyme from M. barkeri and A. fulgidus already showed these properties, activity and stability, at much lower concentrations of these strong salting-out salts.
- Subjects :
- Crystallography, X-Ray
Environment
Hydroxymethyl and Formyl Transferases classification
Hydroxymethyl and Formyl Transferases genetics
Models, Molecular
Phylogeny
Protein Structure, Quaternary
Protein Subunits
Temperature
Ultracentrifugation
Archaeoglobus fulgidus enzymology
Euryarchaeota enzymology
Evolution, Molecular
Hydroxymethyl and Formyl Transferases chemistry
Hydroxymethyl and Formyl Transferases metabolism
Methanosarcina barkeri enzymology
Subjects
Details
- Language :
- English
- ISSN :
- 0961-8368
- Volume :
- 11
- Issue :
- 9
- Database :
- MEDLINE
- Journal :
- Protein science : a publication of the Protein Society
- Publication Type :
- Academic Journal
- Accession number :
- 12192072
- Full Text :
- https://doi.org/10.1110/ps.0211002