Molecular characterization of a conserved archaeal copper resistance (cop) gene cluster and its copper-responsive regulator in Sulfolobus solfataricus P2.
Using a comparative genomics approach, a copper resistance gene cluster has been identified in multiple archaeal genomes. The cop cluster is predicted to encode a metallochaperone (CopM), a P-type copper-exporting ATPase (CopA) and a novel, archaea-specific transcriptional regulator (CopT) which might control the expression of the cop genes. Sequence analysis revealed that CopT has an N-terminal DNA-binding helix-turn-helix domain and a C-terminal TRASH domain; TRASH is a novel domain which has recently been proposed to be uniquely involved in metal-binding in sensors, transporters and trafficking proteins in prokaryotes. The present study describes the molecular characterization of the cop gene cluster in the thermoacidophilic crenarchaeon Sulfolobus solfataricus. The polycistronic copMA transcript was found to accumulate in response to growth-inhibiting copper concentrations, whereas copT transcript abundance appeared to be constitutive. DNA-binding assays revealed that CopT binds to the copMA promoter at multiple sites, both upstream and downstream of the predicted TATA-BRE site. Copper was found to specifically modulate the affinity of DNA binding by CopT. This study describes a copper-responsive operon in archaea, a new family of archaeal DNA-binding proteins, and supports the idea that this domain plays a prominent role in the archaeal copper response. A model is proposed for copper-responsive transcriptional regulation of the copMA gene cluster.
Ettema
Thijs J G
TJG
Laboratory of Microbiology, Wageningen University, Hesselink van Suchtelenweg 4, 6703 CT Wageningen, The Netherlands.
Brinkman
Arie B
AB
Laboratory of Microbiology, Wageningen University, Hesselink van Suchtelenweg 4, 6703 CT Wageningen, The Netherlands.
Lamers
Packo P
PP
Laboratory of Microbiology, Wageningen University, Hesselink van Suchtelenweg 4, 6703 CT Wageningen, The Netherlands.
Kornet
Noor G
NG
Laboratory of Microbiology, Wageningen University, Hesselink van Suchtelenweg 4, 6703 CT Wageningen, The Netherlands.
de Vos
Willem M
WM
Laboratory of Microbiology, Wageningen University, Hesselink van Suchtelenweg 4, 6703 CT Wageningen, The Netherlands.
van der Oost
John
J
Laboratory of Microbiology, Wageningen University, Hesselink van Suchtelenweg 4, 6703 CT Wageningen, The Netherlands.
D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D003300:Copper / Q000494:pharmacology*; D004247:DNA / Q000378:metabolism; D004351:Drug Resistance; D004492:Edetic Acid / Q000494:pharmacology; D019848:Gene Expression Regulation, Archaeal; D008969:Molecular Sequence Data; D005810:Multigene Family; D011401:Promoter Regions, Genetic; D048229:Sulfolobus solfataricus / Q000187:drug effects / Q000235:genetics*
D003300:Copper; D004247:DNA; D004492:Edetic Acid