Structure of haptoglobin heavy chain and other serine protease homologs by comparative model building
Proteins often occur in families whose structure is closely similar, even though the proteins may come from widely different sources and have quite distinct functions. It would be useful to be able to construct the three-dimensional structure of these proteins from the known structure of one or more of them without having to solve the structure of each protein ab initio. We have been using comparative model building to derive the structure of an unusual protein of the trypsin-like serine protease family. We have recently extended this comparison to include other serine protease homologs for which a primary structure is available. To generate structures for the different members of the serine protease family, it is necessary to extract the common structural features of the molecule. Fortunately, three independently determined protein structures are available: schymotrypsin, trypsin, and elastase. These three structures were compared in detail and the structurally conserved regions in all three, mainly the BETA-sheet and the ..cap alpha..-helix, were identified. The variable portions occur in the loops on the surface of the molecule. By using these structures, the primary sequences of these three proteins were aligned. From this alignment, it is clear that sequence homology between the proteins occurs mainly in the structurally conserved regions of the molecule, while the variable portions show very little sequence homology.
- Research Organization:
- Columbia Univ., New York, NY (United States)
- OSTI ID:
- 6796191
- Journal Information:
- Biophys. J.; (United States), Vol. 32:1
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
HAPTOGLOBINS
STRUCTURAL CHEMICAL ANALYSIS
MOLECULAR STRUCTURE
BIOLOGICAL MODELS
PEPTIDE HYDROLASES
COMPARATIVE EVALUATIONS
MOLECULAR BIOLOGY
SERINE
AMINO ACIDS
CARBOHYDRATES
CARBOXYLIC ACIDS
ENZYMES
GLOBULINS
GLOBULINS-ALPHA
HYDROLASES
HYDROXY ACIDS
MUCOPROTEINS
ORGANIC ACIDS
ORGANIC COMPOUNDS
POLYSACCHARIDES
PROTEINS
SACCHARIDES
550200* - Biochemistry
551000 - Physiological Systems