2JSX

Solution structure of the E. coli Tat proofreading chaperone protein NapD

Summary for 2JSX

• Entry DOI: 10.2210/pdb2jsx/pdb
• NMR Information: BMRB: 15381
• Descriptor: Protein napD (1 entity in total)
• Functional Keywords: napd, tat, proofreading, protein, cytoplasm, chaperone
• Biological source: Escherichia coli K12
• Total number of polymer chains: 1
• Total formula weight: 10546.59

Authors

Spronk, C.A.E.M.,Vuister, G.W.,Sargent, F. (deposition date: 2007-07-17, release date: 2007-08-21, Last modification date: 2024-05-08)

Primary citation

Maillard, J.,Spronk, C.A.E.M.,Buchanan, G.,Lyall, V.,Richardson, D.J.,Palmer, T.,Vuister, G.W.,Sargent, F.
Structural diversity in twin-arginine signal peptide-binding proteins.
Proc.Natl.Acad.Sci.Usa, 104:15641-15646, 2007

PubMed Abstract: The twin-arginine transport (Tat) system is dedicated to the translocation of folded proteins across the bacterial cytoplasmic membrane. Proteins are targeted to the Tat system by signal peptides containing a twin-arginine motif. In Escherichia coli, many Tat substrates bind redox-active cofactors in the cytoplasm before transport. Coordination of cofactor insertion with protein export involves a "Tat proofreading" process in which chaperones bind twin-arginine signal peptides, thus preventing premature export. The initial Tat signal-binding proteins described belonged to the TorD family, which are required for assembly of N- and S-oxide reductases. Here, we report that E. coli NapD is a Tat signal peptide-binding chaperone involved in biosynthesis of the Tat-dependent nitrate reductase NapA. NapD binds tightly and specifically to the NapA twin-arginine signal peptide and suppresses signal peptide translocation activity such that transport via the Tat pathway is retarded. High-resolution, heteronuclear, multidimensional NMR spectroscopy reveals the 3D solution structure of NapD. The chaperone adopts a ferredoxin-type fold, which is completely distinct from the TorD family. Thus, NapD represents a new family of twin-arginine signal-peptide-binding proteins.

PubMed: 17901208
DOI: 10.1073/pnas.0703967104

Experimental method

SOLUTION NMR