An Alternative Role of RluD in the Fidelity of Translation Initiation in Escherichia coli

Lahry, Kuldeep and Gopal, Aiswarya and Sahu, Amit Kumar and Marbaniang, Carmelita Nora and Shah, Riyaz Ahmad and Mehta, Avani and Varshney, Umesh (2022) An Alternative Role of RluD in the Fidelity of Translation Initiation in Escherichia coli. In: Journal of Molecular Biology, 434 (12). ISSN 00222836

PDF jou_mol_bio_434-12_2022.pdf - Published Version Restricted to Registered users only Download (2MB) | Request a copy

Abstract

The fidelity of initiator tRNA (i-tRNA) selection in the ribosomal P-site is a key step in translation initiation. The highly conserved three consecutive G:C base pairs (3GC pairs) in the i-tRNA anticodon stem play a crucial role in its selective binding in the P-site. Mutations in the 3GC pairs (3GC mutant) render the i-tRNA inactive in initiation. Here, we show that a mutation (E265K) in the unique C-terminal tail domain of RluD, a large ribosomal subunit pseudouridine synthase, results in compromised fidelity of initiation and allows initiation with the 3GC mutant i-tRNA. RluD modifies the uridine residues in H69 to pseudouridines. However, the role of its C-terminal tail domain remained unknown. The E265K mutation does not diminish the pseudouridine synthase activity of RluD, or the growth phenotype of Escherichia coli, or cause any detectable defects in the ribosomal assembly in our assays. However, in our in vivo analyses, we observed that the E265K mutation resulted in increased retention of the ribosome binding factor A (RbfA) on 30S suggesting a new role of RluD in contributing to RbfA release, a function which may be attributed to its (RluD) C-terminal tail domain. The studies also reveal that deficiency of RbfA release from 30S compromises the fidelity of i-tRNA selection in the ribosomal P-site.

Item Type:	Journal Article
Publication:	Journal of Molecular Biology
Publisher:	Academic Press
Additional Information:	The copyright of this article belongs to the Academic Press.
Keywords:	3GC base pairs; initiator tRNA; pseudouridine synthase; RbfA; ribosome biogenesis; RluD; translation initiation
Department/Centre:	Division of Biological Sciences > Microbiology & Cell Biology
Date Deposited:	20 May 2022 11:23
Last Modified:	20 May 2022 11:23
URI:	https://eprints.iisc.ac.in/id/eprint/72333

Actions (login required)

View Item