Swapping structural determinants of ribonucleases: an energetic analysis of the hinge peptide 16-22.
Data(s) |
25/04/1995
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Resumo |
Bovine seminal ribonuclease (BS-RNase) is a homodimeric enzyme strictly homologous to the pancreatic ribonuclease (RNase A). Native BS-RNase is an equilibrium mixture of two distinct dimers differing in the interchange of the N-terminal segments and in their biological properties. The loop 16-22 plays a fundamental role on the relative stability of the two isomers. Both the primary and tertiary structures of the RNase A differ substantially from those of the seminal ribonuclease in the loop region 16-22. To analyze the possible stable conformations of this loop in both enzymes, structure predictions have been attempted, according to a procedure described by Palmer and Scheraga [Palmer, K. A. & Scheraga, H. A. (1992) J. Comput. Chem. 13, 329-350]. Results compare well with experimental x-ray structures and clarify the structural determinants that are responsible for the swapping of the N-terminal domains and for the peculiar properties of BS-RNase. Minimal modifications of RNase A sequence needed to form a stable swapped dimer are also predicted. |
Identificador |
/pmc/articles/PMC42049/ /pubmed/7731986 |
Idioma(s) |
en |
Publicador |
National Academy of Sciences |
Palavras-Chave | #Research Article |
Tipo |
Text |