Protein chaperones Q8ZP25_SALTY from Salmonella typhimurium and HYAE_ECOLI from Escherichia coli exhibit thioredoxin-like structures despite lack of canonical thioredoxin active site sequence motive

• Published in: Journal of structural and functional genomics Vol. 9; no. 1-4; pp. 41 - 49
• Main Authors: Parish, David, Benach, Jordi, Liu, Goahua, Singarapu, Kiran Kumar, Xiao, Rong, Acton, Thomas, Su, Min, Bansal, Sonal, Prestegard, James H., Hunt, John, Montelione, Gaetano T., Szyperski, Thomas
• Format: Journal Article
• Language: English
• Published: 26.11.2008
• ISSN: 1345-711X; 1570-0267
• DOI: 10.1007/s10969-008-9050-y

The structure of the 142-residue protein Q8ZP25_SALTY encoded in the genome of Salmonella typhimurium LT2 was determined independently by NMR and X-ray crystallography, and the structure of the 140-residue protein HYAE_ECOLI encoded in the genome of Eschericia coli was determined by NMR. The two proteins belong to Pfam [ 1 ] PF07449, which currently comprises 50 members, and belongs itself to the ‘thioredoxin-like clan’. However, protein HYAE_ECOLI and the other proteins of Pfam PF07449 do not contain the canonical Cys-X-X-Cys active site sequence motif of thioredoxin. Protein HYAE_ECOLI was previously classified as a [NiFe] hydrogenase-1 specific chaperone interacting with the twin-arginine translocation (Tat) signal peptide. The structures presented here exhibit the expected thioredoxin-like fold and support the view that members of Pfam family PF07449 specifically interact with Tat signal peptides.