Document Detail


The allosteric regulation of pyruvate kinase by fructose-1,6-bisphosphate.
MedLine Citation:
PMID:  9519410     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: Yeast pyruvate kinase (PK) catalyzes the final step in glycolysis. The enzyme therefore represents an important control point and is allosterically activated by fructose-1,6-bisphosphate (FBP). In mammals the enzyme is found as four different isozymes with different regulatory properties: two of these isozymes are produced by alternate splicing. The allosteric regulation of PK is directly related to proliferation of certain cell types, as demonstrated by the expression of an allosterically regulated isozyme in tumor cells. A model for the allosteric transition from the inactive (T) state to the active (R) state has been proposed previously, but until now the FBP-binding site had not been identified. RESULTS: We report here the structures of PK from yeast complexed with a substrate analog and catalytic metal ions in the presence and absence of bound FBP. The allosteric site is located 40 A from the active site and is entirely located in the enzyme regulatory (C) domain. A phosphate-binding site for the allosteric activator is created by residues encoded by a region of the gene corresponding to the alternately spliced exon of mammalian isozymes. FBP activation appears to induce several conformational changes among active-site sidechains through a mechanism that is most likely to involve significant domain motions, as previously hypothesized. CONCLUSIONS: The structure and location of the allosteric activator site agrees with the pattern of alternate genetic splicing of the PK gene in multicellular eukaryotes that distinguishes between a non-regulated isozyme and the regulated fetal isozymes. The conformational differences observed between the active sites of inactive and fully active PK enzymes is in agreement with the recently determined thermodynamic mechanism of allosteric activation through a 'metal relay' that increases the affinity of the enzyme for its natural phosphoenolpyruvate substrate.
Authors:
M S Jurica; A Mesecar; P J Heath; W Shi; T Nowak; B L Stoddard
Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, Non-P.H.S.; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Structure (London, England : 1993)     Volume:  6     ISSN:  0969-2126     ISO Abbreviation:  Structure     Publication Date:  1998 Feb 
Date Detail:
Created Date:  1998-05-07     Completed Date:  1998-05-07     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  101087697     Medline TA:  Structure     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  195-210     Citation Subset:  IM    
Affiliation:
Molecular and Cellular Biology, Program of the University of Washington, Fred Hutchinson Cancer Research Center, Seattle 98104, USA.
Data Bank Information
Bank Name/Acc. No.:
PDB/1A3W;  1A3X
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Allosteric Regulation
Alternative Splicing
Amino Acid Sequence
Binding Sites
Fructosediphosphates / chemistry*
Genes / genetics
Glycolates / chemistry
Manganese / chemistry
Models, Molecular
Molecular Sequence Data
Phosphoenolpyruvate / chemistry
Potassium / chemistry
Protein Conformation
Pyruvate Kinase / chemistry*,  genetics
Saccharomyces cerevisiae / enzymology*
Chemical
Reg. No./Substance:
0/Fructosediphosphates; 0/Glycolates; 13147-57-4/phosphoglycolate; 488-69-7/fructose-1,6-diphosphate; 73-89-2/Phosphoenolpyruvate; 7439-96-5/Manganese; 7440-09-7/Potassium; EC 2.7.1.40/Pyruvate Kinase

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Structure of Escherichia coli ribokinase in complex with ribose and dinucleotide determined to 1.8 A...
Next Document:  A novel calcium-sensitive switch revealed by the structure of human S100B in the calcium-bound form.