Acta Crystallographica Section F

Structural Biology and Crystallization Communications

Volume 61, Part 12 (December 2005)

structural genomics communications

Acta Cryst. (2005). F61, 1027-1031 [ doi:10.1107/S1744309105035372 ]

Structure of a conserved hypothetical protein, TTHA0849 from Thermus thermophilus HB8, at 2.4 Å resolution: a putative member of the StAR-related lipid-transfer (START) domain superfamily

M. Nakabayashi, N. Shibata, H. Komori, Y. Ueda, H. Iino, A. Ebihara, S. Kuramitsu and Y. Higuchi

Abstract: The crystal structure of a conserved hypothetical protein, TTHA0849 from Thermus thermophilus HB8, has been determined at 2.4 Å resolution as a part of a structural and functional genomics project on T. thermophilus HB8. The main-chain folding shows a compact [alpha] + [beta] motif, forming a hydrophobic cavity in the molecule. A structural similarity search reveals that it resembles those steroidogenic acute regulatory proteins that contain the lipid-transfer (START) domain, even though TTHA0849 shows comparatively weak sequence identity to polyketide cyclases. However, the size of the ligand-binding cavity is distinctly smaller than other START domain-containing proteins, suggesting that it catalyses the transfer of smaller ligand molecules.

PDB reference: 2d4r

Keywords: START domain-containing proteins; structural and functional genomics projects; conserved hypothetical protein TTHA0849.