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Updated: Apr 6, 2026

X-Ray Crystallography to Study the Oligomeric State Transition of the Thermotoga maritima M42 Aminopeptidase TmPep1050
Published on: May 13, 2020
[Physiological and biochemical characteristics of a manganese catalase lacking n-terminal]
Objective:
We characterizeda manganese catalase lacking n-terminal ( MnCAT-C), to revealits roles in bacterial growth, reactive oxygen species ( ROS) removal and degradation of polychlorinated biphenyls ( PCBs) in Rhodococcus sp. R04.
Methods:
Manganese catalase (Mn-CAT) sequence of the strain R04 was aligned with that of Rhodococcus sp. R11101. Mn-CAT and MnCAT-C were expressed in E. coli BL21 (DE3), and the target protein was purified with Q-sepharose and ammonium sulphate precipitation. Knockout strain was obtained by homologous recombination. ROS was measured by fluorescence polarization, and the degradation rate of PCBs was measured by HPLC. [Results] MnCAT-C protein was purified, and SDS-PAGE analysis showed that its molecular weight was 23 kDa. Compared with wild strains, the ROS concentration increased, and the growth rate was inhibited in knockout strains. Moreover, the degradationrate of PCBs decreased. [Conclusion] MnCAT-C retained the majority of the active properties of the original enzyme, including ROS clearance. The lack of MnCAT-C gene affected the growth rate and the PCBsdegradationrate instrain R04.
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