Crystal Structure of the Sugar Binding Domain of the Archaeal Transcriptional Regulator TrmB
Krug, M., Lee, S.J., Diederichs, K., Boos, W., Welte, W.(2006) J Biol Chem 281: 10976-10982
- PubMed: 16473881
- DOI: https://doi.org/10.1074/jbc.M512809200
- Primary Citation of Related Structures:
2F5T - PubMed Abstract:
TrmB is an alpha-glucoside-sensing transcriptional regulator controlling two operons encoding maltose/trehalose and maltodextrin ABC transporters of Pyrococcus furiosus. The crystal structure of an N-terminal truncated derivative of TrmB (amino acids 2-109 deleted; TrmB(delta2-109)) was solved at 1.5 A resolution. This protein has lost its DNA binding domain but has retained its sugar recognition site. The structure represents a novel sugar-binding fold. TrmB(delta2-109) bound maltose, glucose, sucrose, and maltotriose, exhibiting Kd values of 6.8, 25, 34, and 160 microM, respectively. TrmB(delta2-109) behaved as a monomer in dilute buffer solution in contrast to the full-length protein, which is a dimer. Co-crystallization with bound maltose identified a binding site involving seven amino acid residues: Ser229, Asn305, Gly320, Met321, Val324, Ile325, and Glu326. Six of these residues interact with the nonreducing glucosyl residue of maltose. The nonreducing glucosyl residue is shared by all substrates bound to TrmB, suggesting it as a common recognition motif.
Organizational Affiliation:
Department of Biology, University of Konstanz, 78457 Konstanz, Germany.