1CH0
RNASE T1 VARIANT WITH ALTERED GUANINE BINDING SEGMENT
Summary for 1CH0
| Entry DOI | 10.2210/pdb1ch0/pdb |
| Descriptor | PROTEIN (RIBONUCLEASE T1), CALCIUM ION, GUANOSINE-2'-MONOPHOSPHATE, ... (5 entities in total) |
| Functional Keywords | ribonuclease, hydrolase |
| Biological source | Aspergillus oryzae |
| Total number of polymer chains | 3 |
| Total formula weight | 34353.52 |
| Authors | Hoeschler, K.,Hoier, H.,Orth, P.,Hubner, B.,Saenger, W.,Hahn, U. (deposition date: 1999-03-30, release date: 1999-12-22, Last modification date: 2024-11-13) |
| Primary citation | Hoschler, K.,Hoier, H.,Hubner, B.,Saenger, W.,Orth, P.,Hahn, U. Structural analysis of an RNase T1 variant with an altered guanine binding segment. J.Mol.Biol., 294:1231-1238, 1999 Cited by PubMed Abstract: The ribonuclease T1 variant 9/5 with a guanine recognition segment, altered from the wild-type amino acid sequence 41-KYNNYE-46 to 41-EFRNWQ-46, has been cocrystallised with the specific inhibitor 2'-GMP. The crystal structure has been refined to a crystallographic R factor of 0.198 at 2.3 A resolution. Despite a size reduction of the binding pocket, pushing the inhibitor outside by 1 A, 2'-GMP is fixed to the primary recognition site due to increased aromatic stacking interactions. The phosphate group of 2'-GMP is located about 4.2 A apart from its position in wild-type ribonuclease T1-2'-GMP complexes, allowing a Ca(2+), coordinating this phosphate group, to enter the binding pocket. The crystallographic data can be aligned with the kinetic characterisation of the variant, showing a reduction of both, guanine affinity and turnover rate. The presence of Ca(2+) was shown to inhibit variant 9/5 and wild-type enzyme to nearly the same extent. PubMed: 10600381DOI: 10.1006/jmbi.1999.3324 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.3 Å) |
Structure validation
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