TY - JOUR
T1 - Cloning and characterisation of four catA genes located on the chromosome and large plasmid of Pseudomonas putida ND6
AU - Li, Shanshan
AU - Qin, Kun
AU - Li, Huaying
AU - Guo, Jin
AU - Li, Dejin
AU - Liu, Fang
AU - Tan, Zhilei
AU - Yan, Wei
AU - Qu, Shuling
AU - Zhao, Huabing
N1 - Publisher Copyright:
© 2018
PY - 2018/7
Y1 - 2018/7
N2 - Background: Although the functional redundancy of catechol 1,2-dioxygenase (C12O) genes has been reported in several microorganisms, limited enzymes were characterised, let alone the advantage of the coexistence of the multiple copies of C12O genes. Results: In this study, four novel C12O genes, designated catA, catAI, catAII and catAIII, in the naphthalene-degrading strain Pseudomonas putida ND6, were cloned and characterised. Phylogenetic analysis of their deduced amino acid sequences revealed that the four C12O isozymes each formed independent subtrees, together with homologues from other organisms. All four enzymes exhibited maximum activity at pH 7.4 and higher activity in alkaline than in acidic conditions. Furthermore, CatA, CatAI and CatAIII were maximally active at a temperature of 45°C, whereas a higher optimum temperature was observed for CatAII at a temperature of 50°C. CatAI exhibited superior temperature stability compared with the other three C12O isozymes, and kinetic analysis indicated similar enzyme activities for CatA, CatAI and CatAII, whereas that of CatAIII was lower. Significantly, among metal ions tested, only Cu2 + substantially inhibited the activity of these C12O isozymes, thus indicating that they have potential to facilitate bioremediation in environments polluted with aromatics in the presence of metals. Moreover, gene expression analysis at the mRNA level and determination of enzyme activity clearly indicated that the redundancy of the catA genes has increased the levels of C12O. Conclusion: The results clearly imply that the redundancy of catA genes increases the available amount of C12O in P. putida ND6, which would be beneficial for survival in challenging environments. How to cite: Li S, Qin K, Li H, et al. Cloning and characterisation of four catA genes located on the chromosome and large plasmid of Pseudomonas putida ND6. Electron J Biotechnol 2018;34.
AB - Background: Although the functional redundancy of catechol 1,2-dioxygenase (C12O) genes has been reported in several microorganisms, limited enzymes were characterised, let alone the advantage of the coexistence of the multiple copies of C12O genes. Results: In this study, four novel C12O genes, designated catA, catAI, catAII and catAIII, in the naphthalene-degrading strain Pseudomonas putida ND6, were cloned and characterised. Phylogenetic analysis of their deduced amino acid sequences revealed that the four C12O isozymes each formed independent subtrees, together with homologues from other organisms. All four enzymes exhibited maximum activity at pH 7.4 and higher activity in alkaline than in acidic conditions. Furthermore, CatA, CatAI and CatAIII were maximally active at a temperature of 45°C, whereas a higher optimum temperature was observed for CatAII at a temperature of 50°C. CatAI exhibited superior temperature stability compared with the other three C12O isozymes, and kinetic analysis indicated similar enzyme activities for CatA, CatAI and CatAII, whereas that of CatAIII was lower. Significantly, among metal ions tested, only Cu2 + substantially inhibited the activity of these C12O isozymes, thus indicating that they have potential to facilitate bioremediation in environments polluted with aromatics in the presence of metals. Moreover, gene expression analysis at the mRNA level and determination of enzyme activity clearly indicated that the redundancy of the catA genes has increased the levels of C12O. Conclusion: The results clearly imply that the redundancy of catA genes increases the available amount of C12O in P. putida ND6, which would be beneficial for survival in challenging environments. How to cite: Li S, Qin K, Li H, et al. Cloning and characterisation of four catA genes located on the chromosome and large plasmid of Pseudomonas putida ND6. Electron J Biotechnol 2018;34.
KW - Biodegradation pathways
KW - Bioremediation
KW - C12O
KW - Catechol 1,2-dioxygenase genes
KW - Catechol dioxygenases
KW - Gene redundancy
KW - Isozymes
KW - Microbial degradation
KW - Pseudomonas putida ND6
KW - catA genes redundancy
UR - https://www.scopus.com/pages/publications/85049324034
U2 - 10.1016/j.ejbt.2018.06.001
DO - 10.1016/j.ejbt.2018.06.001
M3 - 文章
AN - SCOPUS:85049324034
SN - 0717-3458
VL - 34
SP - 83
EP - 90
JO - Electronic Journal of Biotechnology
JF - Electronic Journal of Biotechnology
ER -