A Molecular and Phylogenetic Analysis of the Specificity-conferring Code of Adenylation Domains in Peptide Synthesis

Kentucky State University, Frankfort KY

Investigators

Abstract

The majority of cellular peptides and proteins have ribosomal origins, where substrate amino acids are activated by an aminoacyl-tRNA synthetase (AARS). However, amino acids are also activated by non-ribosomal peptide synthetases (NRPS) in some soil bacteria. This multienzyme NRPS complex template consists of iterated modules of adenylation, thiolation, and condensation domains. Adenylation domain of NRPS catalyzes the first step of the catalytic reaction as the AARS. A recent study indicates that the adenylation domain not only activates an amino acid, but also an aryl acid. In the preliminary studies, a tryptophanyl t-RNA synthetase (Trp-RS) with residues of adenylation domain using NRPS primers has been identified. This divulges a putative biosynthetic and/or phylogenetic relationship between these two synthetic pathways. This project focuses on the hypothesis that during the course of evolution, the necessity to maintain metabolic activation of a given amino acid pressured the adenylation domain to perform as surrogate-activator and later to diverge into NRPS pathway. Since both complex biosynthetic variations often exist in soil bacteria and they adopt NRPS pathways more habitually, this project performs molecular and phylogenetic analysis of the specificity-conferring codes of the adenylation domain of Trp-RS in three different soil bacteria. The intellectual merit of this project includes the investigation of the involvement of the adenylation domain and the contribution to the overall understanding of the relationship between ribosomal and non-ribosomal peptide synthesis. Broader Impacts: This project will include training of undergraduates in a HBCU institute, thereby helping the institute to retain the minority students who are interested in molecular sciences and research endeavors. The project will provide technical training to a minority candidate and undergraduate students. This project allows for integration of research in education. It will involve dissemination of the techniques and approaches in the 'Advanced Biotechnology' course. Additionally, it will provide workshop training to a group of ten K-12 teachers in Modern Molecular Biology.