Loss of cytochrome c oxidase activity and acquisition of resistance to quinone analogs in a laccase-positive variant of Azospirillum lipoferum - Archive ouverte HAL Access content directly
Journal Articles Journal of Bacteriology Year : 1999

Loss of cytochrome c oxidase activity and acquisition of resistance to quinone analogs in a laccase-positive variant of Azospirillum lipoferum

(1) , (1) , (2) , (2)
1
2

Abstract

Laccase, a p-diphenol oxidase typical of plants and fungi, has been found recently in a proteobacterium, Azospirillum lipoferum. Laccase activity was detected in both a natural isolate and an in vitro-obtained phase variant that originated from the laccase-negative wild type. In this study, the electron transport systems of the laccase-positive variant and its parental laccase-negative forms were compared. During exponential (but not stationary) growth under fully aerobic (but not under microaerobic) conditions, the laccase-positive variant lost a respiratory branch that is terminated in a cytochrome c oxidase of the aa(3) type; this was most likely due to a defect in the biosynthesis of a heme component essential for the oxidase. The laccase-positive variant was significantly less sensitive to the inhibitory action of quinone analogs and fully resistant to inhibitors of the be complex, apparently due to the rearrangements of its respiratory system. We propose that the loss of the cytochrome c oxidase-containing branch in the variant is an adaptive strategy to the presence of intracellular oxidized quinones, the products of laccase activity.

Dates and versions

hal-02868637 , version 1 (15-06-2020)

Identifiers

Cite

Gladys Alexandre, René Bally, B. L. Taylor, I. B. Zhulin. Loss of cytochrome c oxidase activity and acquisition of resistance to quinone analogs in a laccase-positive variant of Azospirillum lipoferum. Journal of Bacteriology, 1999, 181 (21), pp.6730-6738. ⟨10.1128/JB.181.21.6730-6738.1999⟩. ⟨hal-02868637⟩
11 View
0 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More