کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2816499 1159937 2014 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The relation between hairpin formation by mitochondrial WANCY tRNAs and the occurrence of the light strand replication origin in Lepidosauria
کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی ژنتیک
پیش نمایش صفحه اول مقاله
The relation between hairpin formation by mitochondrial WANCY tRNAs and the occurrence of the light strand replication origin in Lepidosauria
چکیده انگلیسی


• After loss of mitochondrial replication origin (OL)
• Adjacent tDNAs increase formation of OL-like structures.
• In several independent reptile lineages
• OL function increase is inversely proportional
• To translational functional pressures on the tRNA

Mitochondrial light strand DNA replication is initiated at light strand replication origins (OLs), short stem-loop hairpins formed by the heavy strand DNA. OL-like secondary structures are also formed by heavy strand DNA templating for the five tRNAs adjacent to OLs, the WANCY tRNA cluster. We tested whether natural OL absence associates with greater capacities for formation of OL-like structures by WANCY tRNA genes. Using lepidosaurian taxa (Sphenodon, lizards and amphisbaenids), we compared WANCY tRNA capacities to form OL-like structures between 248 taxa possessing an OL with 131 taxa without OL (from different families). On average, WANCY tRNA genes form more OL-like structures in the absence of a regular OL than in its presence. Formation of OL-like structures by WANCY tRNAs follows hierarchical patterns that may reduce competition between the tRNA's translational function and its secondary OL function: the rarer the tRNA's cognate amino acid, the greater the capacity to form OL-like structures. High OL-forming capacities for neighboring tRNAs are avoided. Because OL absence usually occurs in taxa with reduced genomes, increased formation of OL-like structures by WANCY tRNAs might result from selection for greater metabolic efficiency. Further analyses suggest that OL loss is one of the latest steps in genome reduction, and promotes the increase in formation of OL-like structures by WANCY tRNA genes in Lepidosauria.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Gene - Volume 542, Issue 2, 1 June 2014, Pages 248–257
نویسندگان
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