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Oligomeric status of human cystathionine beta‐synthase modulates AdoMet binding
Author(s) -
Pey Angel L.,
MartínezCruz Luis Alfonso,
Kraus Jan P.,
Majtan Tomas
Publication year - 2016
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1002/1873-3468.12488
Subject(s) - cystathionine beta synthase , enzyme , chemistry , biochemistry , atp synthase , binding site , stereochemistry , cysteine
Cystathionine beta‐synthase ( CBS ) plays a key role in the metabolism of sulfur‐containing amino acids. CBS is a multidomain tetrameric enzyme allosterically activated by S‐adenosylmethionine (AdoMet). Recent crystallographic analyses of engineered CBS lacking the loop made up of residues 516–525 revealed discrepancies in AdoMet binding compared to previous biophysical studies on a full‐length CBS . Here, we show that removal of the loop 516–525 functionally eliminates the high affinity sites responsible for kinetic stabilization of the full‐length enzyme and yields a dimeric AdoMet‐inducible enzyme, in which kinetic stabilization is now exerted by AdoMet binding to the remaining low affinity sites.