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Title: Paradigm Shift for Radical S-Adenosyl-L-methionine Reactions: The Organometallic Intermediate Ω Is Central to Catalysis

Abstract

Radical S-adenosyl-L-methionine (SAM) enzymes comprise a vast superfamily catalyzing diverse reactions essential to all life through homolytic SAM cleavage to liberate the highly reactive 5'-deoxyadenosyl radical (5'-dAdo·). Our recent observation of a catalytically competent organometallic intermediate Ω that forms during reaction of the radical SAM (RS) enzyme pyruvate formate-lyase activating-enzyme (PFL-AE) was therefore quite surprising, and led to the question of its broad relevance in the superfamily. We now show that Ω in PFL-AE forms as an intermediate under a variety of mixing order conditions, suggesting it is central to catalysis in this enzyme. We further demonstrate that Ω forms in a suite of RS enzymes chosen to span the totality of superfamily reaction types, implicating Ω as essential in catalysis across the RS superfamily. Finally, EPR and electron nuclear double resonance spectroscopy establish that Ω involves an Fe-C5' bond between 5'-dAdo· and the [4Fe-4S] cluster. An analogous organometallic bond is found in the well-known adenosylcobalamin (coenzyme B 12) cofactor used to initiate radical reactions via a 5'- dAdo· intermediate. Liberation of a reactive 5'-dAdo· intermediate via homolytic metal-carbon bond cleavage thus appears to be similar for Ω and coenzyme B 12. However, coenzyme B 12 is involved in enzymesmore » catalyzing only a small number (~12) of distinct reactions, whereas the RS superfamily has more than 100 000 distinct sequences and over 80 reaction types characterized to date. The appearance of Ω across the RS superfamily therefore dramatically enlarges the sphere of bio-organometallic chemistry in Nature.« less

Authors:
 [1];  [2];  [1];  [2];  [1];  [1];  [1];  [1];  [3];  [3];  [1];  [1];  [4];  [4];  [5]; ORCiD logo [5];  [1]; ORCiD logo [2]; ORCiD logo [1]
  1. Montana State Univ., Bozeman, MT (United States)
  2. Northwestern Univ., Evanston, IL (United States)
  3. Eidgenössische Technische Hochschule Zürich (Switzerland)
  4. Cassia, LLC, San Diego, CA (United States)
  5. Duke University Medical Center, Durham, NC (United States)
Publication Date:
Research Org.:
Montana State Univ., Bozeman, MT (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1459248
Alternate Identifier(s):
OSTI ID: 1508581
Grant/Contract Number:  
SC0005404
Resource Type:
Published Article
Journal Name:
Journal of the American Chemical Society
Additional Journal Information:
Journal Volume: 140; Journal Issue: 28; Journal ID: ISSN 0002-7863
Publisher:
American Chemical Society (ACS)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY

Citation Formats

Byer, Amanda S., Yang, Hao, McDaniel, Elizabeth C., Kathiresan, Venkatesan, Impano, Stella, Pagnier, Adrien, Watts, Hope, Denler, Carly, Vagstad, Anna L., Piel, Jörn, Duschene, Kaitlin S., Shepard, Eric M., Shields, Thomas P., Scott, Lincoln G., Lilla, Edward A., Yokoyama, Kenichi, Broderick, William E., Hoffman, Brian M., and Broderick, Joan B. Paradigm Shift for Radical S-Adenosyl-L-methionine Reactions: The Organometallic Intermediate Ω Is Central to Catalysis. United States: N. p., 2018. Web. doi:10.1021/jacs.8b04061.
Byer, Amanda S., Yang, Hao, McDaniel, Elizabeth C., Kathiresan, Venkatesan, Impano, Stella, Pagnier, Adrien, Watts, Hope, Denler, Carly, Vagstad, Anna L., Piel, Jörn, Duschene, Kaitlin S., Shepard, Eric M., Shields, Thomas P., Scott, Lincoln G., Lilla, Edward A., Yokoyama, Kenichi, Broderick, William E., Hoffman, Brian M., & Broderick, Joan B. Paradigm Shift for Radical S-Adenosyl-L-methionine Reactions: The Organometallic Intermediate Ω Is Central to Catalysis. United States. doi:10.1021/jacs.8b04061.
Byer, Amanda S., Yang, Hao, McDaniel, Elizabeth C., Kathiresan, Venkatesan, Impano, Stella, Pagnier, Adrien, Watts, Hope, Denler, Carly, Vagstad, Anna L., Piel, Jörn, Duschene, Kaitlin S., Shepard, Eric M., Shields, Thomas P., Scott, Lincoln G., Lilla, Edward A., Yokoyama, Kenichi, Broderick, William E., Hoffman, Brian M., and Broderick, Joan B. Thu . "Paradigm Shift for Radical S-Adenosyl-L-methionine Reactions: The Organometallic Intermediate Ω Is Central to Catalysis". United States. doi:10.1021/jacs.8b04061.
@article{osti_1459248,
title = {Paradigm Shift for Radical S-Adenosyl-L-methionine Reactions: The Organometallic Intermediate Ω Is Central to Catalysis},
author = {Byer, Amanda S. and Yang, Hao and McDaniel, Elizabeth C. and Kathiresan, Venkatesan and Impano, Stella and Pagnier, Adrien and Watts, Hope and Denler, Carly and Vagstad, Anna L. and Piel, Jörn and Duschene, Kaitlin S. and Shepard, Eric M. and Shields, Thomas P. and Scott, Lincoln G. and Lilla, Edward A. and Yokoyama, Kenichi and Broderick, William E. and Hoffman, Brian M. and Broderick, Joan B.},
abstractNote = {Radical S-adenosyl-L-methionine (SAM) enzymes comprise a vast superfamily catalyzing diverse reactions essential to all life through homolytic SAM cleavage to liberate the highly reactive 5'-deoxyadenosyl radical (5'-dAdo·). Our recent observation of a catalytically competent organometallic intermediate Ω that forms during reaction of the radical SAM (RS) enzyme pyruvate formate-lyase activating-enzyme (PFL-AE) was therefore quite surprising, and led to the question of its broad relevance in the superfamily. We now show that Ω in PFL-AE forms as an intermediate under a variety of mixing order conditions, suggesting it is central to catalysis in this enzyme. We further demonstrate that Ω forms in a suite of RS enzymes chosen to span the totality of superfamily reaction types, implicating Ω as essential in catalysis across the RS superfamily. Finally, EPR and electron nuclear double resonance spectroscopy establish that Ω involves an Fe-C5' bond between 5'-dAdo· and the [4Fe-4S] cluster. An analogous organometallic bond is found in the well-known adenosylcobalamin (coenzyme B12) cofactor used to initiate radical reactions via a 5'- dAdo· intermediate. Liberation of a reactive 5'-dAdo· intermediate via homolytic metal-carbon bond cleavage thus appears to be similar for Ω and coenzyme B12. However, coenzyme B12 is involved in enzymes catalyzing only a small number (~12) of distinct reactions, whereas the RS superfamily has more than 100 000 distinct sequences and over 80 reaction types characterized to date. The appearance of Ω across the RS superfamily therefore dramatically enlarges the sphere of bio-organometallic chemistry in Nature.},
doi = {10.1021/jacs.8b04061},
journal = {Journal of the American Chemical Society},
number = 28,
volume = 140,
place = {United States},
year = {2018},
month = {6}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
DOI: 10.1021/jacs.8b04061

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Cited by: 9 works
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