Evolution of substrate specificity in a recipient's enzyme following horizontal gene transfer.

Authors:
Dr. Mauricio Carrillo-Tripp, PhD
Dr. Mauricio Carrillo-Tripp, PhD
Biomolecular Diversity Laboratory, Cinvestav
Associate Profesor
Computational Biophysics
Irapuato, Guanajuato | México
Vilmos Fulop
Vilmos Fulop
University of Warwick

Mol Biol Evol 2013 Sep 25;30(9):2024-34. Epub 2013 Jun 25.

Evolution of Metabolic Diversity Laboratory, Laboratorio Nacional de Genómica para la Biodiversidad (Langebio), Cinvestav-IPN, Irapuato, México.

Despite the prominent role of horizontal gene transfer (HGT) in shaping bacterial metabolism, little is known about the impact of HGT on the evolution of enzyme function. Specifically, what is the influence of a recently acquired gene on the function of an existing gene? For example, certain members of the genus Corynebacterium have horizontally acquired a whole l-tryptophan biosynthetic operon, whereas in certain closely related actinobacteria, for example, Mycobacterium, the trpF gene is missing. In Mycobacterium, the function of the trpF gene is performed by a dual-substrate (βα)8 phosphoribosyl isomerase (priA gene) also involved in l-histidine (hisA gene) biosynthesis. We investigated the effect of a HGT-acquired TrpF enzyme upon PriA's substrate specificity in Corynebacterium through comparative genomics and phylogenetic reconstructions. After comprehensive in vivo and enzyme kinetic analyses of selected PriA homologs, a novel (βα)8 isomerase subfamily with a specialized function in l-histidine biosynthesis, termed subHisA, was confirmed. X-ray crystallography was used to reveal active-site mutations in subHisA important for narrowing of substrate specificity, which when mutated to the naturally occurring amino acid in PriA led to gain of function. Moreover, in silico molecular dynamic analyses demonstrated that the narrowing of substrate specificity of subHisA is concomitant with loss of ancestral protein conformational states. Our results show the importance of HGT in shaping enzyme evolution and metabolism.

Download full-text PDF

Source
http://dx.doi.org/10.1093/molbev/mst115DOI Listing

Still can't find the full text of the article?

We can help you send a request to the authors directly.
September 2013
28 Reads
13 Citations
9.110 Impact Factor

Publication Analysis

Top Keywords

substrate specificity
16
narrowing substrate
8
horizontal gene
8
gene transfer
8
hgt shaping
8
trpf gene
8
gene
7
enzyme
5
function
5
enzyme kinetic
4
reconstructions comprehensive
4
comprehensive vivo
4
vivo enzyme
4
kinetic analyses
4
analyses selected
4
pria homologs
4
subfamily specialized
4
specialized function
4
function l-histidine
4
isomerase subfamily
4

Similar Publications