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Borrelia burgdorferi bb0728 encodes a coenzyme A disulphide reductase whose function suggests a role in intracellular redox and the oxidative stress response
Author(s) -
Boylan Julie A.,
Hummel Charles S.,
Benoit Stéphane,
GarciaLara Jorge,
TreglownDowney Jennifer,
Crane Edward J.,
Gherardini Frank C.
Publication year - 2006
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.2005.04963.x
Subject(s) - biology , biochemistry , glutathione , intracellular , borrelia burgdorferi , oxidative stress , thioredoxin , glutathione reductase , reductase , thioredoxin reductase , enzyme , glutathione peroxidase , antibody , immunology
Summary The cellular responses of Borrelia burgdorferi To reactive oxygen species (ROS) encountered during the different stages of its infective cycle are poorly understood. Few enzymes responsible for protecting proteins, DNA/RNA and lipids from damage by ROS have been identified and characterized. Data presented here suggest that bb0728 encodes an enzyme involved in this process. Biochemical analyses on purified recombinant BB0728 indicated that it functioned as a coenzyme A disulphide reductase (CoADR) (specific activity ≈ 26 units per mg of protein). This enzyme was specific for coenzyme A (CoA) disulphide, required NADH and had no significant activity against other disulphides, such as oxidized glutathione or thioredoxin. The high intracellular concentration of reduced CoA (CoASH) in B. burgdorferi cells (∼1 mM) and absence of glutathione suggest that CoA is the major low‐molecular‐weight thiol in this spirochete. Interestingly, CoASH was able to reduce H 2 O 2 and be regenerated by CoADR suggesting one role for the system may be to protect B. burgdorferi from ROS. Further, mobility‐shift assays and transcriptional fusion data indicated that bb0728 was positively regulated by the Borrelia oxidative stress response regulator, BosR. Taken together, these data suggest a role for BB0728 in intracellular redox and the oxidative stress response in B. burgdorferi .