Evolution of substrate specificity in a retained enzyme driven by gene loss
Abstract
The connection between gene loss and the functional adaptation of retained proteins is still poorly understood. We apply phylogenomics and metabolic modeling to detect bacterial species that are evolving by gene loss, with the finding that Actinomycetaceae genomes from human cavities are undergoing sizable reductions, including loss of L-histidine and L-tryptophan biosynthesis. We observe that the dual-substrate phosphoribosyl isomerase A or priA gene, at which these pathways converge, appears to coevolve with the occurrence of trp and his genes. Characterization of a dozen PriA homologs shows that these enzymes adapt from bifunctionality in the largest genomes, to a monofunctional, yet not necessarily specialized, inefficient form in genomes undergoing reduction. These functional changes are accomplished via mutations, which result from relaxation of purifying selection, in residues structurally mapped after sequence and X-ray structural analyses. Our results show how gene loss can drive the evolution of substrate specificity from retained enzymes.
Data availability
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The Whole Genome Shotgun (WGS) A. oris MG-1 projectPublicly available at the NCBI Nucleotide (accession no: MAUB00000000).
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Actinomyces oris strain:MG-1 Genome sequencing and assemblyPublicly available at the NCBI BioProject (accession no: PRJNA327886.
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Actinomycetaceae Phylogenomics: Comparative Analysis of ModelsPublicly available, subject to registering an account, at KBase (accession no: ws.17193.obj.1).
Article and author information
Author details
Funding
Consejo Nacional de Ciencia y Tecnología (132376,179290)
- Ana Lilia Juárez-Vázquez
- Ernesto A Verduzco-Castro
- Julián Santoyo-Flores
- Mauricio Carrillo-Tripp
National Institutes of Health (GM094585)
- Karolina Michalska
- Gyorgy Babnigg
- Michael Endres
- Andrzej Joachimiak
US Department of Energy (DE-AC02-06CH11357)
- Andrzej Joachimiak
- Christopher S Henry
National Science Foundation (1611952)
- Janaka E Edirisinghe
- Christopher S Henry
National Institute of Dental and Craniofacial Research (DE017382)
- Chenggang Wu
- Hung Ton-That
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Reviewing Editor
- Alfonso Valencia, Barcelona Supercomputing Center - BSC, Spain
Version history
- Received: October 25, 2016
- Accepted: March 25, 2017
- Accepted Manuscript published: March 31, 2017 (version 1)
- Version of Record published: April 25, 2017 (version 2)
Copyright
This is an open-access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.
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