An evolutionarily conserved element in initiator tRNAs prompts ultimate steps in ribosome maturation

Shetty, Sunil and Varshney, Umesh (2016) An evolutionarily conserved element in initiator tRNAs prompts ultimate steps in ribosome maturation. In: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 113 (41). E6126-E6134.

PDF Pro_Nat_Aca_Sci_Uni_Sta_Ame_113-41_E6123_2016.pdf - Published Version Restricted to Registered users only Download (1MB) | Request a copy

Abstract

Ribosome biogenesis, a complex multistep process, results in correct folding of rRNAs, incorporation of >50 ribosomal proteins, and their maturation. Deficiencies in ribosome biogenesis may result in varied faults in translation of mRNAs causing cellular toxicities and ribosomopathies in higher organisms. How cells ensure quality control in ribosome biogenesis for the fidelity of its complex function remains unclear. Using Escherichia coli, we show that initiator tRNA (i-tRNA), specifically the evolutionarily conserved three consecutive GC base pairs in its anticodon stem, play a crucial role in ribosome maturation. Deficiencies in cellular contents of i-tRNA confer cold sensitivity and result in accumulation of ribosomes with immature 3' and 5' ends of the 16S rRNA. Overexpression of i-tRNA in various strains rescues biogenesis defects. Participation of i-tRNA in the first round of initiation complex formation licenses the final steps of ribosome maturation by signaling RNases to trim the terminal extensions of immature 16S rRNA.

Item Type:	Journal Article
Publication:	PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
Additional Information:	Copy right for this article belongs to this NATL ACAD SCIENCES, 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA
Department/Centre:	Division of Biological Sciences > Microbiology & Cell Biology
Date Deposited:	03 Dec 2016 06:21
Last Modified:	03 Dec 2016 06:21
URI:	http://eprints.iisc.ac.in/id/eprint/55268

Actions (login required)

View Item