Open AccessStructure of the regulatory subunit of CK2 in the presence of a p21 WAF1 peptide demonstrates flexibility of the acidic loop
Author(s) -
Bertrand Loic,
Sayed Muhammed F. R.,
Pei XueYuan,
Parisini Emilio,
Dhanaraj Venugopal,
BolanosGarcia Victor M.,
Allende Jorge E.,
Blundell Tom L.
Publication year - 2004
Publication title -
acta crystallographica section d
Language(s) - English
Resource type - Journals
ISSN - 1399-0047
DOI - 10.1107/s0907444904016750
Subject(s) - dimer , protein subunit , structural similarity , stereochemistry , chemistry , peptide , peptide sequence , crystallography , biochemistry , gene , organic chemistry
A truncated form of the regulatory subunit of the protein kinase CK2β (residues 1–178) has been crystallized in the presence of a fragment of the cyclin‐dependent kinase inhibitor p21 WAF1 (residues 46–65) and the structure solved at 2.9 Å resolution by molecular replacement. The core of the CK2β dimer shows a high structural similarity with that identified in previous structural analyses of the dimer and the holoenzyme. However, the electron density corresponding to the substrate‐binding acidic loop (residues 55–64) indicates two conformations that differ from that of the holoenzyme structure [Niefind et al. (2001), EMBO J. 20 , 5320–5331]. Difference electron density near the dimerization region in each of the eight protomers in the asymmetric unit is attributed to between one and eight amino‐acid residues of a complexed fragment of p21 WAF1 . This binding site corresponds to the solvent‐accessible part of the conserved zinc‐finger motif.