|
|
| Line 1: |
Line 1: |
| [[Image:1m5h.gif|left|200px]] | | {{Seed}} |
| | [[Image:1m5h.png|left|200px]] |
|
| |
|
| <!-- | | <!-- |
| Line 9: |
Line 10: |
| {{STRUCTURE_1m5h| PDB=1m5h | SCENE= }} | | {{STRUCTURE_1m5h| PDB=1m5h | SCENE= }} |
|
| |
|
| '''Formylmethanofuran:tetrahydromethanopterin formyltransferase from Archaeoglobus fulgidus'''
| | ===Formylmethanofuran:tetrahydromethanopterin formyltransferase from Archaeoglobus fulgidus=== |
|
| |
|
|
| |
|
| ==Overview==
| | <!-- |
| 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.
| | The line below this paragraph, {{ABSTRACT_PUBMED_12192072}}, adds the Publication Abstract to the page |
| | (as it appears on PubMed at http://www.pubmed.gov), where 12192072 is the PubMed ID number. |
| | --> |
| | {{ABSTRACT_PUBMED_12192072}} |
|
| |
|
| ==About this Structure== | | ==About this Structure== |
| Line 32: |
Line 36: |
| [[Category: Tziatzios, C.]] | | [[Category: Tziatzios, C.]] |
| [[Category: Alpha/beta sandwich]] | | [[Category: Alpha/beta sandwich]] |
| ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 00:39:28 2008'' | | |
| | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Wed Jul 2 23:15:21 2008'' |
