Publication Date:
1992-10-02
Description:
The smooth muscle myosin light chain kinase (smMLCK) catalytic core was modeled by using the crystallographic coordinates of the cyclic AMP-dependent protein kinase catalytic subunit (cAPK) and a bound pseudosubstrate inhibitor peptide, PKI(5-24). Despite only 30% identity in amino acid sequence, the MLCK sequence can be readily accommodated in this structure. With the exception of the short B-helix, all major elements of secondary structure in the core are very likely conserved. The active site of the modeled MLCK complements the known requirements for peptide substrate recognition. MLCK contains a pseudosubstrate sequence that overlaps the calmodulin binding domain and has been proposed to act as an intrasteric inhibitor and occupy the substrate binding site in the absence of Ca(2+)-calmodulin. The pseudosubstrate sequence can be modeled easily into the entire backbone of PKI(5-24). The results demonstrate that the intrasteric model for regulation of MLCK by intramolecular competitive inhibition is structurally plausible.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Knighton, D R -- Pearson, R B -- Sowadski, J M -- Means, A R -- Ten Eyck, L F -- Taylor, S S -- Kemp, B E -- T32CA09523/CA/NCI NIH HHS/ -- T32DK07233/DK/NIDDK NIH HHS/ -- New York, N.Y. -- Science. 1992 Oct 2;258(5079):130-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry, University of California San Diego, La Jolla 92093-0654.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1439761" target="_blank"〉PubMed〈/a〉
Keywords:
Amino Acid Sequence
;
Binding Sites
;
Chromosome Mapping
;
Crystallography
;
*Gene Expression Regulation, Enzymologic
;
Models, Molecular
;
Molecular Sequence Data
;
Molecular Structure
;
Myosin-Light-Chain Kinase/*chemistry
;
Oligopeptides/genetics/metabolism
;
Peptide Fragments
;
Peptides/genetics/metabolism
;
Protein Binding/physiology
;
Protein Kinases/chemistry
;
Sequence Alignment
;
Sequence Homology
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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