The coding sequence of the hemolytically inactive C4A6 allotype of human complement component C4 reveals that a single arginine to tryptophan substitution at beta-chain residue 458 is the likely cause of the defect.

Abstract excerpt

The C4A6 allotype of the human complement component C4 is known to be defective in C5 binding within the C5 convertase. To characterize the position and nature of the molecular defect in the C4A6 allotype we have isolated the C4A6 gene from a cosmid genomic DNA library. Direct sequencing of a 4.4-kb region of the gene covering exons 17 to 31 and encoding the C4d fragment and most of the rest of the alpha chain of...

Topics

• Alleles
• Amino Acid Sequence
• Base Sequence
• Blotting, Southern
• Chromosome Mapping
• Cloning, Molecular
• Complement C4a
• Complement C5
• Cosmids
• Exons