Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2001-2-22
pubmed:abstractText
The human genome, as in other eukaryotes, has a wide heterogeneity in the DNA base composition. The evolutionary basis for this heterogeneity has been unknown. A previous study of the human genome (846 genes analyzed) has shown that, in the major range of the G+C content in the third codon position (0.25-0.75), biases from the Parity Rule 2 (PR2) among the synonymous codons of the four-codon amino acids are similar except in the highest G+C range (Sueoka, N., 1999. Translation-coupled violation of Parity Rule 2 in human genes is not the cause of heterogeneity of the DNA G+C content of third codon position. Gene 238, 53-58.). PR2 is an intra-strand rule where A=T and G=C are expected when there are no biases between the two complementary strands of DNA in mutation and selection rates (substitution rates). In this study, 14,026 human genes were analyzed. In addition, the third codon positions of two-codon amino acids were analyzed. New results show the following: (a) The G+C contents of the third codon position of human genes are scattered in the G+C range of 0.22-0.96 in the third codon position. (b) The PR2 biases are similar in the range of 0.25-0.75, whereas, in the high G+C range (0.75-0.96; 13% of the genes), the PR2-bias fingerprints are different from those of the major range. (c) Unlike the PR2 biases, the G+C contents of the third codon position for both four-codon and two-codon amino acids are all correlated almost perfectly with the G+C content of the third codon position over the total G+C ranges. These results support the notion that the directional mutation pressure, rather than the directional selection pressure, is mainly responsible for the heterogeneity of the G+C content of the third codon position.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0378-1119
pubmed:author
pubmed:issnType
Print
pubmed:day
30
pubmed:volume
261
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
53-62
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
DNA G+C content of the third codon position and codon usage biases of human genes.
pubmed:affiliation
University of Colorado, Department of Molecular, Cellular, and Developmental Biology, Boulder, CO 80309-0347, USA. sueoka@stripe.colorado.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't