Abstract:
:Interactions within the decoding center of the 30 S ribosomal subunit have been investigated by constructing all 15 possible mutations at nucleotides C1402 and A1500 in helix 44 of 16 S rRNA. As expected, most of the mutations resulted in highly deleterious phenotypes, consistent with the high degree of conservation of this region and its functional importance. A total of seven mutants were viable under conditions where the mutant ribosomes comprised 100 % of the ribosomal pool. A suppressor mutation specific for the C1402U-A1500G mutant was isolated at position 1520 in helix 45 of 16 S rRNA. In addition, lack of dimethylation of A1518/A1519 caused by mutation of the ksgA methylase enhanced the deleterious effect of many of the 1402/1500 mutations. These data suggest that a higher-order interaction between helices 44 and 45 in 16 S rRNA is important for the proper functioning of the ribosome. This is consistent with the recent high-resolution crystal structures of the 30 S subunit, which show a tertiary interaction between the 1402/1500 region of helix 44 and the dimethyl A stem loop.
journal_name
J Mol Bioljournal_title
Journal of molecular biologyauthors
Vila-Sanjurjo A,Dahlberg AEdoi
10.1006/jmbi.2001.4576keywords:
subject
Has Abstractpub_date
2001-05-04 00:00:00pages
457-63issue
3eissn
0022-2836issn
1089-8638pii
S0022-2836(01)94576-0journal_volume
308pub_type
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