Evidence map›Paper›PMID 40247822›Full record

ArticleProtein science : a publication of the Protein Society2025

Intramolecular epistasis correlates with divergence of specificity in promiscuous and bifunctional NSAR/OSBS enzymes.

Dat P Truong, Roopa Dharmatti, Dylan Suriadinata, Jamison Huddleston, Rebecca Skouby, Gladys Owusu Addo, Mingzhao Zhu, Anjana Delpe Acharige, Reethu Sankari Bayana, Cristian Davila and 5 more

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In one paragraph

Article in Protein science : a publication of the Protein Society, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

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3 · Its place in the literature

Who cites it

2 citing papers in PubMed.

  1. Construction of a linezolid-resistant strain of methicillin-susceptibleFrontiers in cellular and infection microbiology · 2026
    Article
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4 · The record

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PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

15 authors.

Dat P TruongDepartment of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, USA.
Roopa DharmattiDepartment of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, USA.
Dylan SuriadinataDepartment of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, USA.
Jamison HuddlestonDepartment of Chemistry, Texas A&M University, College Station, Texas, USA.
Rebecca SkoubyDepartment of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, USA.
Gladys Owusu AddoDepartment of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, USA.
Mingzhao ZhuDepartment of Chemistry and Biochemistry & Baylor Synthesis and Drug Lead Discovery Laboratory, Baylor University, Waco, Texas, USA.
Anjana Delpe AcharigeDepartment of Chemistry and Biochemistry & Baylor Synthesis and Drug Lead Discovery Laboratory, Baylor University, Waco, Texas, USA.
Reethu Sankari BayanaDepartment of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, USA.
Cristian DavilaDepartment of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, USA.
Susan C FultsDepartment of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, USA.
Frank M RaushelDepartment of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, USA.
Kenneth G HullDepartment of Chemistry and Biochemistry & Baylor Synthesis and Drug Lead Discovery Laboratory, Baylor University, Waco, Texas, USA.
Daniel RomoDepartment of Chemistry and Biochemistry & Baylor Synthesis and Drug Lead Discovery Laboratory, Baylor University, Waco, Texas, USA.
Margaret E GlasnerDepartment of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, USA.ORCID 0000-0003-1818-1965

Funding

National Science Foundation CAREER Award 1253975NIGMS NIH HHS R01-GM124409Welch Foundation A-1991-20190330
6 · The paper itself

Abstract

Understanding the functions and evolution of specificity-determining residues is essential for improving strategies to predict and design enzyme functions. Whether the function of an amino acid residue is retained during evolution depends on intramolecular epistasis, which occurs when the same residue contributes to different phenotypes in different genetic backgrounds. This study examines the relationship between epistasis and functional divergence by investigating a conserved specificity determinant in five homologs from the N-succinylamino acid racemase (NSAR)/o-succinylbenzoate synthase (OSBS) subfamily. NSAR activity originated as a promiscuous (non-biological) activity of an ancestral OSBS. Some extant NSAR/OSBS subfamily enzymes still have OSBS activity as a biological function and NSAR as a promiscuous activity, while some use both OSBS and NSAR activities as biological functions. Others use only NSAR activity as a biological function but can still catalyze the OSBS reaction as a promiscuous activity. Previously, we determined that the conserved residue R266 in Amycolatopsis sp. T-1-60 NSAR contributes to NSAR specificity by enabling K263 to act as a general acid/base catalyst. Here, we show that mutating R266 decreased relative specificity for NSAR activity in four of five NSAR/OSBS subfamily enzymes, as predicted. However, other phenotypes exhibited epistasis related to the pleiotropy of R266, including the proton exchange rate between the catalytic lysines and the substrate, the impact on OSBS activity, and thermostability. The strength of epistasis was associated with functional and evolutionary divergence of NSAR/OSBS enzymes. These results illustrate the benefits of comparing multiple homologs for understanding mechanisms of enzyme specificity.

Indexed as

Amino Acid IsomerasesBacterial ProteinsEpistasis, GeneticEvolution, MolecularSubstrate SpecificityAmino Acid IsomerasesBacterial Proteinscatalytic promiscuityenzyme evolutionenzyme specificityepistasis

Identifiers

PMID40247822
PMCPMC12006748

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.