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pyruvate kinase M-type (PKM)

Function: - glycolytic enzyme that catalyzes the transfer of a phosphoryl group from phosphoenolpyruvate (PEP) to ADP, generating ATP - isoform M2 is allosterically activated by D-fructose 1,6-biphosphate (FBP) - carbohydrate degradation; glycolysis pyruvate from D-glyceraldehyde 3-phosphate: step 5/5 - phosphorylated upon DNA damage, probably by ATM or ATR ATP + pyruvate ADP + phosphoenolpyruvate Cofactors: Mg+2, K+ Kinetic parameters: - KM=2.7 mM for phosphoenolpyruvate# - KM=0.17 mM for phosphoenolpyruvate (in the presence of 2mM FBP) - KM=0.34 mM for ADP - KM=0.24 mM for ADP (in the presence of 2mM FBP) # at pH=8 & 32 degrees celsius inhibited by oxalate Structure: homotetramer belongs to the pyruvate kinase family Alternative splicing: named isoforms=2 Expression: - early fetal tissues as well as in most cancer cells Note: - 4 isozymes of pyruvate kinase in mammals: L, R, M1 & M2 - L type is major isozyme in the liver - R is found in red cells - M1 is the main form in muscle, heart & brain - M2 is found in early fetal tissues as well as in most cancer cells Genetics: - M1 & M2 isoforms from same gene, by alternative splicing

Specific

pyruvate kinase M1 [muscle] (cytosolic thyroid hormone-binding protein) pyruvate kinase M2 (PKM2)

General

pyruvate kinase

Properties

CONFIGURATION: tetramer SIZE: entity length = 531 aa MW = 58 kD COMPARTMENT: cytoplasm CELL: unspecified cell type WITHIN: muscle brain MOTIF: Ser phosphorylation site {S37} Thr phosphorylation site {T45} Tyr phosphorylation site {Y83} Tyr phosphorylation site {Y105} Tyr phosphorylation site {Y148} lysine residue {K270} Mg+2-binding site SITE: 272-272 Mg+2-binding site SITE: 296-296 Thr phosphorylation site {T328} Intersubunit contact {389-433} MOTIF: Tyr phosphorylation site {Y390} allosteric {432-437} binding site SITE: 482-482 FOR-BINDING-OF: fructose-1,6-diphosphate binding site SITE: 489-489 FOR-BINDING-OF: fructose-1,6-diphosphate allosteric {514-521}

Database Correlations

OMIM 179050 UniProt P14618 PFAM correlations Kegg hsa:5315 ENZYME 2.7.1.40

References

  1. UniProt :accession P14786
  2. Wikipedia; Note: pyruvate kinase entry http://en.wikipedia.org/wiki/pyruvate_kinase
  3. Stryer Biochemistry WH Freeman & Co, New York,1988 pg 362
  4. Wikipedia; Note: pyruvate kinase entry http://en.wikipedia.org/wiki/pyruvate_kinase