Carbamoyl phosphate synthetase: a tunnel runs through it

Curr Opin Struct Biol. 1998 Dec;8(6):679-85. doi: 10.1016/s0959-440x(98)80086-9.


The direct transfer of metabolites from one protein to another in a biochemical pathway or between one active site and another within a single enzyme has been described as substrate channeling. The first structural visualization of such a phenomenon was provided by the X-ray crystallographic analysis of tryptophan synthase, in which a tunnel of approximately 25 A in length was observed. The recently determined three-dimensional structure of carbamoyl phosphate synthetase sets a new long distance record in that the three active sites are separated by nearly 100 A.

Publication types

  • Review

MeSH terms

  • Binding Sites
  • Biopolymers
  • Carbamoyl-Phosphate Synthase (Glutamine-Hydrolyzing) / chemistry*
  • Carbamoyl-Phosphate Synthase (Glutamine-Hydrolyzing) / metabolism
  • Crystallography, X-Ray
  • Protein Conformation


  • Biopolymers
  • Carbamoyl-Phosphate Synthase (Glutamine-Hydrolyzing)