From Proteopedia
(Difference between revisions)
proteopedia linkproteopedia link
|
|
| Line 1: |
Line 1: |
| - | [[Image:1goc.gif|left|200px]] | + | {{Seed}} |
| | + | [[Image:1goc.png|left|200px]] |
| | | | |
| | <!-- | | <!-- |
| Line 9: |
Line 10: |
| | {{STRUCTURE_1goc| PDB=1goc | SCENE= }} | | {{STRUCTURE_1goc| PDB=1goc | SCENE= }} |
| | | | |
| - | '''COOPERATIVE STABILIZATION OF ESCHERICHIA COLI RIBONUCLEASE HI BY INSERTION OF GLY-80B AND GLY-77-> ALA SUBSTITUTION'''
| + | ===COOPERATIVE STABILIZATION OF ESCHERICHIA COLI RIBONUCLEASE HI BY INSERTION OF GLY-80B AND GLY-77-> ALA SUBSTITUTION=== |
| | | | |
| | | | |
| - | ==Overview==
| + | <!-- |
| - | The insertion of a Gly residue (designated as Gly-80b) between the C-cap of the alpha II-helix (Gln-80) and the N-cap of the alpha III-helix (Trp-81) in Escherichia coli ribonuclease HI enhances the protein stability by 0.4 kcal/mol in delta G (Kimura, S., Nakamura, H., Hashimoto, T., Oobatake, M., & Kanaya, S. (1992) J. Biol. Chem. 267, 21535-21542). Another mutation within the alpha II-helix, Gly-77-->Ala, reduces the stability by 0.9 kcal/mol. Simultaneous introduction of these mutations enhances the stability by 0.8 kcal/mol, indicating that the effects of these mutations are cooperative and not simply independent. We determined the crystal structures of these three mutant proteins (G80b-, A77-, and A77/G80b-RNase H) to investigate this cooperative mechanism of the protein stabilization. The structures revealed that the inserted Gly-80b assumes a left-handed helical conformation in both the G80b- and the A77/G80b-RNase H. This inserted glycine residue allows the formation of a "paperclip", which is a common motif at the C-termini of alpha-helices. Accompanying the formation of the paperclip motif, two intrahelical hydrogen bonds are formed between the backbone atoms (O78-N80b and O80b-N84). The stabilization caused by the insertion of Gly-80b can be ascribed to the formation of these hydrogen bonds. The Gly-77-->Ala substitution destabilizes the protein due to the deformed packing interactions in the hydrophobic core around Ala-77 and the stress in the wedged indole ring of Trp-81. These effects are alleviated by the insertion of Gly-80b, which relaxes the backbone structure.(ABSTRACT TRUNCATED AT 250 WORDS) | + | The line below this paragraph, {{ABSTRACT_PUBMED_8393706}}, adds the Publication Abstract to the page |
| | + | (as it appears on PubMed at http://www.pubmed.gov), where 8393706 is the PubMed ID number. |
| | + | --> |
| | + | {{ABSTRACT_PUBMED_8393706}} |
| | | | |
| | ==About this Structure== | | ==About this Structure== |
| Line 28: |
Line 32: |
| | [[Category: Morikawa, K.]] | | [[Category: Morikawa, K.]] |
| | [[Category: Nakamura, H.]] | | [[Category: Nakamura, H.]] |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 17:49:06 2008'' | + | |
| | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Tue Jul 1 05:36:03 2008'' |
Revision as of 02:36, 1 July 2008
Template:STRUCTURE 1goc
COOPERATIVE STABILIZATION OF ESCHERICHIA COLI RIBONUCLEASE HI BY INSERTION OF GLY-80B AND GLY-77-> ALA SUBSTITUTION
Template:ABSTRACT PUBMED 8393706
About this Structure
1GOC is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Cooperative stabilization of Escherichia coli ribonuclease HI by insertion of Gly-80b and Gly-77-->Ala substitution., Ishikawa K, Nakamura H, Morikawa K, Kimura S, Kanaya S, Biochemistry. 1993 Jul 20;32(28):7136-42. PMID:8393706
Page seeded by OCA on Tue Jul 1 05:36:03 2008
