Title: Structural and functional characterization of three Type B and C chloramphenicol acetyltransferases from Vibrio species

Abstract

Chloramphenicol acetyltransferases (CATs) were among the first antibiotic resistance enzymes identified and have long been studied as model enzymes for examining plasmid-mediated antibiotic resistance. These enzymes acetylate the antibiotic chloramphenicol, which renders it incapable of inhibiting bacterial protein synthesis. CATs can be classified into different types: Type A CATs are known to be important for antibiotic resistance to chloramphenicol and fusidic acid. Type B CATs are often called xenobiotic acetyltransferases and adopt a similar structural fold to streptogramin acetyltransferases, which are known to be critical for streptogramin antibiotic resistance. Type C CATs have recently been identified and can also acetylate chloramphenicol, but their roles in antibiotic resistance are largely unknown. In this work, we structurally and kinetically characterized three Vibrio CAT proteins from a nonpathogenic species (Aliivibrio fisheri) and two important human pathogens (Vibrio cholerae and Vibrio vulnificus). We found all three proteins, including one in a superintegron (V. cholerae), acetylated chloramphenicol, but did not acetylate aminoglycosides or dalfopristin. We also determined the 3D crystal structures of these CATs alone and in complex with crystal violet and taurocholate. These compounds are known inhibitors of Type A CATs, but have not been explored in Type B and Type C CATs. Basedmore » on sequence, structure, and kinetic analysis, we concluded that the V. cholerae and V. vulnificus CATs belong to the Type B class and the A. fisheri CAT belongs to the Type C class. Ultimately, our results provide a framework for studying the evolution of antibiotic resistance gene acquisition and chloramphenicol acetylation in Vibrio and other species.« less

Authors:

Alcala, Ashley ^[1]; Ramirez, Guadalupe ^[1]; Solis, Allan ^[1]; Kim, Youngchang ^[2]; Tan, Kemin ^[2]; Luna, Oscar ^[1]; Nguyen, Karen ^[1]; Vazquez, Daniel ^[1]; Ward, Michael ^[1]; Zhou, Min ^[2]; Mulligan, Rory ^[2]; Maltseva, Natalia ^[2]; Kuhn, Misty L.  ^[1]

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+ Show Author Affiliations

1. San Francisco State Univ., CA (United States)
2. Univ. of Chicago, IL (United States); Argonne National Lab. (ANL), Argonne, IL (United States)

Publication Date:

Sun Nov 24 00:00:00 EST 2019

Research Org.:

Argonne National Laboratory (ANL), Argonne, IL (United States). Advanced Photon Source (APS)

Sponsoring Org.:

National Institute of Allergy and Infectious Diseases (NIAID); National Institutes of Health (NIH); National Science Foundation (NSF); USDOE Office of Science (SC)

OSTI Identifier:

1615515

Alternate Identifier(s):

OSTI ID: 1577415

Grant/Contract Number:  

AC02-06CH11357; HHSN272201200026C; HHSN272201700060C; CHE-1708863

Resource Type:

Accepted Manuscript

Journal Name:

Protein Science

Additional Journal Information:

Journal Volume: 29; Journal Issue: 3; Journal ID: ISSN 0961-8368

Publisher:

The Protein Society

Country of Publication:

United States

Language:

English

Subject:

59 BASIC BIOLOGICAL SCIENCES; Aliivibrio fischeri; antibiotic resistance; biochemical education; chloramphenicol acetyltransferase; functional characterization; gene annotation; integron; Vibrio cholerae; Vibrio vulnificus; xenobiotic acetyltransferase