Title: Enzymatic β-Oxidation of the Cholesterol Side Chain in Mycobacterium tuberculosis Bifurcates Stereospecifically at Hydration of 3-Oxo-cholest-4,22-dien-24-oyl-CoA

Abstract

The unique ability of Mycobacterium tuberculosis (Mtb) to utilize host lipids such as cholesterol for survival, persistence, and virulence has made the metabolic pathway of cholesterol an area of great interest for therapeutics development. Herein, we identify and characterize two genes from the Cho-region (genomic locus responsible for cholesterol catabolism) of the Mtb genome, chsH3 (Rv3538) and chsB1 (Rv3502c). Their protein products catalyze two sequential stereospecific hydration and dehydrogenation steps in the β-oxidation of the cholesterol side chain. ChsH3 favors the 22S hydration of 3-oxo-cholest-4,22-dien24-oyl-CoA in contrast to the previously reported EchA19 (Rv3516), which catalyzes formation of the (22R)-hydroxy-3-oxo-cholest4-en-24-oyl-CoA from the same enoyl-CoA substrate. ChsB1 is stereospecific and catalyzes dehydrogenation of the ChsH3 product but not the EchA19 product. The X-ray crystallographic structure of the ChsB1 apo-protein was determined at a resolution of 2.03 Å, and the holo-enzyme with bound NAD⁺ cofactor was determined at a resolution of 2.21 Å. The homodimeric structure is representative of a classical NAD⁺-utilizing short-chain type alcohol dehydrogenase/reductase, including a Rossmann-fold motif, but exhibits a unique substrate binding site architecture that is of greater length and width than its homologous counterparts, likely to accommodate the bulky steroid substrate. Intriguingly, Mtb utilizes hydratases from the MaoC-likemore » family in sterol side-chain catabolism in contrast to fatty acid β-oxidation in other species that utilize the evolutionarily distinct crotonase family of hydratases.« less

Authors:

Yuan, Tianao  ^[1];

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• Search DOE PAGES for ORCID "0000-0002-4700-8654"

Werman, Joshua M.  ^[1];

• Search DOE PAGES for author "Werman, Joshua M."
• Search DOE PAGES for ORCID "0000-0002-8521-7369"

Yin, Xingyu  ^[2];

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• Search DOE PAGES for ORCID "0000-0003-3832-0547"

Yang, Meng  ^[1];

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• Search DOE PAGES for ORCID "0000-0002-1371-5844"

Garcia-Diaz, Miguel  ^[3];

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• Search DOE PAGES for ORCID "0000-0003-1605-6861"

Sampson, Nicole S.  ^[1]

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• Search DOE PAGES for ORCID "0000-0002-2835-7760"

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+ Show Author Affiliations

1. Stony Brook Univ., NY (United States). Dept. of Chemistry
2. Stony Brook Univ., NY (United States). Biochemistry and Structural Biology Graduate Program
3. Stony Brook Univ., NY (United States). Dept. of Pharmacological Sciences

Publication Date:

Wed Apr 07 00:00:00 EDT 2021

Research Org.:

Brookhaven National Lab. (BNL), Upton, NY (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences & Biosciences Division

OSTI Identifier:

1816192

Grant/Contract Number:  

SC0012704

Resource Type:

Accepted Manuscript

Journal Name:

ACS Infectious Diseases

Additional Journal Information:

Journal Volume: 7; Journal Issue: 6; Journal ID: ISSN 2373-8227

Publisher:

American Chemical Society (ACS)

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 59 BASIC BIOLOGICAL SCIENCES; Mycobacterium tuberculosis; cholesterol; catabolism; stereochemistry; Rv3538; Rv3502c; degradation; peptides and proteins; conformation; hydration