The C-terminal domain of eukaryotic initiation factor 5 promotes start codon recognition by its dynamic interplay with eIF1 and eIF2 beta

Recognition of the proper start codon on mRNAs is essential for protein synthesis, which requires scanning and involves eukaryotic initiation factors (eIFs) eIF1, eIF1A, eIF2, and eIF5. The carboxyl terminal domain (CTD) of eIF5 stimulates 43S preinitiation complex (PIC) assembly; however, its precise role in scanning and start codon selection has remained unknown. Using nuclear magnetic resonance (NMR) spectroscopy, we identified the binding sites of eIF1 and eIF2β on eIF5-CTD and found that they partially overlapped. Mutating select eIF5 residues in the common interface specifically disrupts interaction with both factors. Genetic and biochemical evidence indicates that these eIF5-CTD mutations impair start codon recognition and impede eIF1 release from the PIC by abrogating eIF5-CTD binding to eIF2β. This study provides mechanistic insight into the role of eIF5-CTD's dynamic interplay with eIF1 and eIF2β in switching PICs from an open to a closed state at start codons.publishedVersio

The Mercury Resistance (Mer) Operon In A Marine Gliding Flavobacterium, Tenacibaculum Discolor 9a5

Genes conferring mercury resistance have been investigated in a variety of bacteria and archaea but not in bacteria of the phylum Bacteroidetes, despite their importance in many environments. We found, however, that a marine gliding Bacteroidetes species, Tenacibaculum discolor, was the predominant mercury-resistant bacterial taxon cultured from a salt marsh fertilized with mercury-contaminated sewage sludge. Here we report characterization of the mercuric reductase and the narrow-spectrum mercury resistance (mer) operon from one of these strains T. discolor 9A5. This mer operon, which confers mercury resistance when cloned into Flavobacterium johnsoniae, encodes a novel mercury-responsive ArsR/SmtB family transcriptional regulator that appears to have evolved independently from other mercury-responsive regulators, a novel putative transport protein consisting of a fusion between the integral membrane Hg(II) transporter MerT and the periplasmic Hg(II)-binding protein MerP, an additional MerP protein, and a mercuric reductase that is phylogenetically distinct from other known mercuric reductases

The C-terminal domain of eukaryotic initiation factor 5 promotes start codon recognition by its dynamic interplay with eIF1 and eIF2 beta

Recognition of the proper start codon on mRNAs is essential for protein synthesis, which requires scanning and involves eukaryotic initiation factors (eIFs) eIF1, eIF1A, eIF2, and eIF5. The carboxyl terminal domain (CTD) of eIF5 stimulates 43S preinitiation complex (PIC) assembly; however, its precise role in scanning and start codon selection has remained unknown. Using nuclear magnetic resonance (NMR) spectroscopy, we identified the binding sites of eIF1 and eIF2β on eIF5-CTD and found that they partially overlapped. Mutating select eIF5 residues in the common interface specifically disrupts interaction with both factors. Genetic and biochemical evidence indicates that these eIF5-CTD mutations impair start codon recognition and impede eIF1 release from the PIC by abrogating eIF5-CTD binding to eIF2β. This study provides mechanistic insight into the role of eIF5-CTD's dynamic interplay with eIF1 and eIF2β in switching PICs from an open to a closed state at start codons

Management development: a literature review and implications for future research - Part II: Profiles and Contexts

In this second and concluding part of an extensive review of the management development literature, attention is directed to studies which have sought to describe and explain how managers are in fact made and to studies which have emphasised the contextual aspects of the process. The review is concluded with an overall assessment of the management development literature – its strengths and weaknesses – and with an analysis of the implications which this assessment carries for the conduct of future research. Crucial gaps are identified, not least of which is a general failure to locate descriptions of particular management development initiatives within the context of other ways in which the management stock is enhanced, replenished and managed. Another major shortcoming which is singled out as requiring urgent attention is the failure to place management development accounts and prescriptions within the wider context of organisational characteristics