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Genetic Modification of Cyanobacteria by Conjugation Using the CyanoGate Modular Cloning Toolkit
Published on: October 31, 2019
[A putative NtcA-regulating gene, alr1390, in Anabaena sp. PCC 7120]
Mengying Liu1, Li Wang, Wenli Chen
1State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China. liumengying@webmail.hzau.edu.cn
Unlabelled:
NtcA is a master transcriptional regulator in global nitrogen control in Anabaena. Heterocyst differentiation depends on the NtcA protein. A large number of genes regulated by NtcA have a consensus sequence, GTA-N8-TAC, for NtcA binding. Bioinformatics analysis of alr1390 in the chromosome of Anabaena sp. PCC 7120 indicates that there is a conservative NtcA binding box, GTA-TAGTTTTC-TAC, upstream the putative tsp position of alr1390.
Objective:
To understand the relationship between alr1390 and NtcA, METHODS: Real-time RT-PCR and EMSA were used.
Results:
Real-time RT-PCR results showed that the transcriptional level of alr1390 remained constant before and after combined nitrogen step-down in wild type Anabaena sp. PCC 7120. However, in the ntcA mutant, there was an increase in the transcriptional level of alr1390 after 12h of combined nitrogen step-down, which indicated that alr1390 should be subject to the regulation of NtcA. Additionally although no conspicuous NtcA-alr1390 complex was detected by EMSA in vitro, a smear appeared in gel electrophoresis.
Conclusion:
These results suggested that alr1390 might be regulated by NtcA.
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