Allosteric histidine switch for regulation of intracellular zinc(II) fluctuation.
Proc Natl Acad Sci U S A
; 114(52): 13661-13666, 2017 12 26.
Article
em En
| MEDLINE
| ID: mdl-29229866
ABSTRACT
Metalloregulators allosterically control transcriptional activity through metal binding-induced reorganization of ligand residues and/or hydrogen bonding networks, while the coordination atoms on the same ligand residues remain seldom changed. Here we show that the MarR-type zinc transcriptional regulator ZitR switches one of its histidine nitrogen atoms for zinc coordination during the allosteric control of DNA binding. The Zn(II)-coordination nitrogen on histidine 42 within ZitR's high-affinity zinc site (site 1) switches from Nε2 to Nδ1 upon Zn(II) binding to its low-affinity zinc site (site 2), which facilitates ZitR's conversion from the nonoptimal to the optimal DNA-binding conformation. This histidine switch-mediated cooperation between site 1 and site 2 enables ZitR to adjust its DNA-binding affinity in response to a broad range of zinc fluctuation, which may allow the fine tuning of transcriptional regulation.
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Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Zinco
/
Histidina
Idioma:
En
Ano de publicação:
2017
Tipo de documento:
Article