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2gb1
From Proteopedia
A NOVEL, HIGHLY STABLE FOLD OF THE IMMUNOGLOBULIN BINDING DOMAIN OF STREPTOCOCCAL PROTEIN G
Overview
The high-resolution three-dimensional structure of a single immunoglobulin binding domain (B1, which comprises 56 residues including the NH2-terminal Met) of protein G from group G Streptococcus has been determined in solution by nuclear magnetic resonance spectroscopy on the basis of 1058 experimental restraints. The average atomic root-mean-square distribution about the mean coordinate positions is 0.27 angstrom (A) for the backbone atoms, 0.65 A for all atoms, and 0.39 A for atoms excluding disordered surface side chains. The structure has no disulfide bridges and is composed of a four-stranded beta sheet, on top of which lies a long helix. The central two strands (beta 1 and beta 4), comprising the NH2- and COOH-termini, are parallel, and the outer two strands (beta 2 and beta 3) are connected by the helix in a +3x crossover. This novel topology (-1, +3x, -1), coupled with an extensive hydrogen-bonding network and a tightly packed and buried hydrophobic core, is probably responsible for the extreme thermal stability of this small domain (reversible melting at 87 degrees C).
About this Structure
2GB1 is a Single protein structure of sequence from Bacteria. Full crystallographic information is available from OCA.
Reference
A novel, highly stable fold of the immunoglobulin binding domain of streptococcal protein G., Gronenborn AM, Filpula DR, Essig NZ, Achari A, Whitlow M, Wingfield PT, Clore GM, Science. 1991 Aug 9;253(5020):657-61. PMID:1871600 Page seeded by OCA on Sun May 4 04:54:09 2008
