Publication Type |
Journal Article |
School or College |
School of Medicine |
Department |
Human Genetics |
Creator |
Gesteland, Raymond F.; Atkins, John F.; Baranov, Pavel V. |
Other Author |
Vestergaard, Bente; Nyborg, Jens; Hamelryck, Thomas |
Title |
Diverse bacterial genomes encode an operon of two genes, one of which is an unusual class-I release factor that potentially recognizes atypical mRNA signals other than normal stop codons |
Date |
2006 |
Description |
ABSTRACT: Background: While all codons that specify amino acids are universally recognized by tRNA molecules, codons signaling termination of translation are recognized by proteins known as class-I release factors (RF). In most eukaryotes and archaea a single RF accomplishes termination at all three stop codons. In most bacteria, there are two RFs with overlapping specificity, RF1 recognizes UA(A/G) and RF2 recognizes U(A/G)A. The hypothesis: First, we hypothesize that orthologues of the E. coli K12 pseudogene prfH encode a third class-I RF that we designate RFH. Second, it is likely that RFH responds to signals other than conventional stop codons. Supporting evidence comes from the following facts: (i) A number of bacterial genomes contain prfH orthologues with no discernable interruptions in their ORFs. (ii) RFH shares strong sequence similarity with other class-I bacterial RFs. (iii) RFH contains a highly conserved GGQ motif associated with peptidyl hydrolysis activity (iv) residues located in the areas supposedly interacting with mRNA and the ribosomal decoding center are highly conserved in RFH, but different from other RFs. RFH lacks the functional, but non-essential domain 1. Yet, RFH-encoding genes are invariably accompanied by a highly conserved gene of unknown function, which is absent in genomes that lack a gene for RFH. The accompanying gene is always located upstream of the RFH gene and with the same orientation. The proximity of the 3' end of the former with the 5' end of the RFH gene makes it likely that their expression is co-regulated via translational coupling. In summary, RFH has the characteristics expected for a class-I RF, but likely with different specificity than RF1 and RF2. Testing the hypothesis: The most puzzling question is which signals RFH recognizes to trigger its release function. Genetic swapping of RFH mRNA recognition components with its RF1 or RF2 counterparts may reveal the nature of RFH signals. Implications of the hypothesis: The hypothesis implies a greater versatility of release-factor like activity in the ribosomal Asite than previously appreciated. A closer study of RFH may provide insight into the evolution of the genetic code and of the translational machinery responsible for termination of translation. |
Type |
Text |
Publisher |
BioMed Central |
Journal Title |
Biology Direct |
Volume |
1 |
Issue |
1 |
First Page |
28 |
DOI |
10.1186/1745-6150-1-28 |
citatation_issn |
17456150 |
Subject |
Class-I release factors; RF1; RF2; Bacterial genomes |
Subject MESH |
Codon, Terminator; Bacteria; Gene Expression Regulation, Bacterial |
Language |
eng |
Bibliographic Citation |
Baranov PV, Vestergaard B, Hamelryck T, Gesteland RF, Nyborg J, Atkins JF. 2006. Diverse bacterial genomes encode an operon of two genes, one of which is an unusual class-I release factor that potentially recognizes atypical mRNA signals other than normal stop codons. Biol Direct 1:28 |
Rights Management |
(c) [Author(s)]. Creative Commons Attribution License http://creativecommons.org/licenses/by/2.0/ |
Format Medium |
application/pdf |
Format Extent |
701,992 Bytes |
Identifier |
ir-main,3775 |
ARK |
ark:/87278/s696023j |
Setname |
ir_uspace |
ID |
706325 |
Reference URL |
https://collections.lib.utah.edu/ark:/87278/s696023j |