The structure of the archaebacterial ribosomal protein S7 and its possible interaction with 16S rRNA.
J Biochem
; 130(5): 695-701, 2001 Nov.
Article
in En
| MEDLINE
| ID: mdl-11686933
ABSTRACT
Ribosomal protein S7 is one of the ubiquitous components of the small subunit of the ribosome. It is a 16S rRNA-binding protein positioned close to the exit of the tRNA, and it plays a role in initiating assembly of the head of the 30S subunit. Previous structural analyses of eubacterial S7 have shown that it has a stable alpha-helix core and a flexible beta-arm. Unlike these eubacterial proteins, archaebacterial or eukaryotic S7 has an N-terminal extension of approximately 60 residues. The crystal structure of S7 from archaebacterium Pyrococcus horikoshii (PhoS7) has been determined at 2.1 A resolution. The final model of PhoS7 consists of six major alpha-helices, a short 3(10)-helix and two beta-stands. The major part (residues 18-45) of the N-terminal extension of PhoS7 reinforces the alpha-helical core by well-extended hydrophobic interactions, while the other part (residues 46-63) is not visible in the crystal and is possibly fixed only by interacting with 16S rRNA. These differences in the N-terminal extension as well as in the insertion (between alpha1 and alpha2) of the archaebacterial S7 structure from eubacterial S7 are such that they do not necessitate a major change in the structure of the currently available eubacterial 16S rRNA. Some of the inserted chains might pass through gaps formed by helices of the 16S rRNA.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Ribosomal Proteins
/
RNA, Ribosomal, 16S
/
Pyrococcus
/
Archaeal Proteins
Limits:
Humans
Language:
En
Journal:
J Biochem
Year:
2001
Document type:
Article