Publication Date:
1991-08-09
Description:
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).〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Gronenborn, A M -- Filpula, D R -- Essig, N Z -- Achari, A -- Whitlow, M -- Wingfield, P T -- Clore, G M -- New York, N.Y. -- Science. 1991 Aug 9;253(5020):657-61.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1871600" target="_blank"〉PubMed〈/a〉
Keywords:
Amino Acid Sequence
;
Bacterial Proteins/*chemistry/immunology
;
Binding Sites
;
Calorimetry
;
Hydrogen Bonding
;
*Immunoglobulin G
;
Magnetic Resonance Spectroscopy/methods
;
Models, Molecular
;
Protein Conformation
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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