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Title: A novel signal transduction protein: Combination of solute binding and tandem PAS-like sensor domains in one polypeptide chain

The tandem Per-Arnt-Sim (PAS) like sensors are commonly found in signal transduction proteins. The periplasmic solute binding protein (SBP) domains are found ubiquitously and are generally involved in solute transport. These domains are widely observed as parts of separate proteins but not within the same polypeptide chain. We report the structural and biochemical characterization of the extracellular ligand-binding receptor, Dret_0059 from Desulfohalobium retbaense DSM 5692, an organism isolated from the Retba salt lake in Senegal. The structure of Dret_0059 consists of a novel combination of SBP and TPAS sensor domains. The N-terminal region forms an SBP domain and the C-terminal region folds into a tandem PAS-like domain structure. A ketoleucine moiety is bound to the SBP, whereas a cytosine molecule is bound in the distal PAS domain of the TPAS. The differential scanning flourimetry studies in solution support the ligands observed in the crystal structure. There are only two other proteins with this structural architecture in the non-redundant sequence data base and we predict that they too bind the same substrates. There is significant interaction between the SBP and TPAS domains, and it is quite conceivable that the binding of one ligand will have an effect on the binding ofmore » the other. Our attempts to remove the ligands bound to the protein during expression were not successful, therefore, it is not clear what the relative affects are. The genomic context of this receptor does not contain any protein components expected for transport function, hence, we suggest that Dret_0059 is likely involved in signal transduction and not in solute transport.« less
 [1] ;  [1] ;  [1] ;  [1] ;  [1] ;  [2] ;  [2] ;  [2] ;  [1] ;  [1]
  1. Argonne National Lab. (ANL), Argonne, IL (United States)
  2. Argonne National Lab. (ANL), Argonne, IL (United States); Univ. of Chicago, Chicago, IL (United States)
Publication Date:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Protein Science
Additional Journal Information:
Journal Volume: 26; Journal Issue: 4; Journal ID: ISSN 0961-8368
The Protein Society
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
National Institutes of Health (NIH); National Institute of General Medical Sciences; USDOE
Country of Publication:
United States
59 BASIC BIOLOGICAL SCIENCES; KIC; Ketoleucine; cytosine; receptor; signal transduction; solute binding protein; tandem PAS-like sensor; ligand-binding protein; protein fold; structure
OSTI Identifier: