1LSQ

RIBONUCLEASE A WITH ASN 67 REPLACED BY A BETA-ASPARTYL RESIDUE

Summary for 1LSQ

• Entry DOI: 10.2210/pdb1lsq/pdb
• Descriptor: RIBONUCLEASE A, SULFATE ION (3 entities in total)
• Functional Keywords: hydrolase, phosphoric diester
• Biological source: Bos taurus (cattle)
• Cellular location: Secreted: P61823
• Total number of polymer chains: 2
• Total formula weight: 27610.75

Authors

Esposito, L.,Sica, F.,Vitagliano, L.,Zagari, A.,Mazzarella, L. (deposition date: 1996-06-25, release date: 1997-01-11, Last modification date: 2024-10-16)

Primary citation

Capasso, S.,Di Donato, A.,Esposito, L.,Sica, F.,Sorrentino, G.,Vitagliano, L.,Zagari, A.,Mazzarella, L.
Deamidation in proteins: the crystal structure of bovine pancreatic ribonuclease with an isoaspartyl residue at position 67.
J.Mol.Biol., 257:492-496, 1996

PubMed Abstract: The non-enzymatic deamidation of asparagine residues in proteins is a widely occurring reaction, both in vivo and in vitro. Although the importance of this process is commonly recognised, only little structural information is available on it. In order to evaluate the structural effects of this reaction in proteins, we have determined the crystal structure of a ribonuclease A derivative in which asparagine 67 has been replaced by an isoaspartyl residue, as a consequence of an in vitro deamidation reaction. The overall structure of the model, refined to a crystallographic R-factor of 0.159 at a resolution of 1.9 A, is very similar to that of the native protein, but considerable deviations are observed in the region delimited by the disulphide bridge 65-72. In particular, the insertion of an extra methylene group in the main chain at residue 67 breaks up the hydrogen bond network that makes this region rather rigid in ribonuclease A. On the basis of the structure observed, some of the slightly but significantly different properties of this deamidated derivative, with respect to the native enzyme, can be explained.

PubMed: 8648618
DOI: 10.1006/jmbi.1996.0179

Experimental method

X-RAY DIFFRACTION (1.9 Å)