The Structures and Related Functions of Phosphorylase a

Fletterick, Robert J.; Madsen, Neil B.

doi:10.1146/annurev.bi.49.070180.000335

Cited by 205 publications

(103 citation statements)

References 70 publications

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“…More than 50 years of research on glycogen phosphorylase in eukaryotes has yielded a rich harvest of ideas and principles, and the glgP genes have been isolated from several eukaryotic organisms [1][2][3][4][5][6][7], but this enzyme is as yet unknown in prokaryotes. There are at least three glycogen-synthesizing enzymes of bacteria, glycogen synthase, branching enzyme, and ADPglucose pyrophosphorylase, which are the gefie products of glgA, gigB, and gigC, respectively [8][9][10][11].…”

Section: Introductionmentioning

confidence: 99%

Molecular cloning and sequencing of the glycogen phosphorylase gene from Escherichia coli

Choi¹,

Kawamukai²,

Utsumi³

et al. 1989

FEBS Letters

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The glgP gene, which codes for glycogen phosphorylase, was cloned from a genomic library of Escherichia coil The nucleotide sequence of the glgP gene contained a single open reading frame encoding a protein consisting of 790 amino acid residues. The glgP gene product, a polypeptide of Mr 87 000, was confirmed by SDS-polyacrylamide gel electrophoresis. The deduced amino acid sequence showed that homology between glgP of E. carl and rabbit glgP, human glgP, potato glgP, and E. coli malP was 48.6, 48.6, 42.3, and 46.1%, respectively. Within this homologous region, the active site, glycogen storage site, and pyridoxal-5'-phosphate binding site are well conserved. The enzyme activity of glycogen phosphorylase increased after introduction on a multicopy of the glgP gene.

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Section: Introductionmentioning

confidence: 99%

Molecular cloning and sequencing of the glycogen phosphorylase gene from Escherichia coli

Choi¹,

Kawamukai²,

Utsumi³

et al. 1989

FEBS Letters

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“…AMP binds to a regulatory site at the subunit interface (Kasvinsky et al, 1978b;Lorek et al, 1984;Sprang et al, 1987Sprang et al, , 1988Sprang et al, , 1991 and drives the dephosphorylated enzyme (phosphorylase b or GPb) toward the R-state. Phosphorylation at Ser 14 produces an active enzyme (phosphorylase a, or GPa) that does not require AMP for activity and binds both AMP and substrates noncooperatively with high affinity (Fletterick & Madsen, 1980). Crystallographic studies of both GPb (Barford & Johnson, 1989;Acharya et al, 1991) and GPa (Sprang & Fletterick, 1979;Sprang et al, 1987Sprang et al, , 1991Withers et al, 1982a;Goldsmith et al, 1989b) bound to a variety of regulatory ligands have revealed a spectrum of conformational substrates, suggesting that a two-state model does not accurately describe the range of structures accessible to the enzyme.…”

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confidence: 99%

Multiple phosphate positions in the catalytic site of glycogen phosphorylase: Structure of the pyridoxal‐5′‐pyrophosphate coenzyme‐substrate analog

Sprang¹,

Madsen²,

Withers³

1992

Protein Science

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The three-dimensional structure of an R-state conformer of glycogen phosphorylase containing the coenzymesubstrate analog pyridoxal-5'-diphosphate at the catalytic site (PLPP-GPb) has been refined by X-ray crystallography to a resolution of 2.87 A. The molecule comprises four subunits of phosphorylase related by approximate 222 symmetry. Whereas the quaternary structure of R-state PLPP-GPb is similar to that of phosphorylase crystallized in the presence of ammonium sulfate (Barford, D. & Johnson, L.N., 1989, Nature 340, 609-616), the tertiary structures differ in that the two domains of the PLPP-GPb subunits are rotated apart by 5" relative to the T-state conformation. Global differences among the four subunits suggest that the major domains of the phosphorylase subunit are connected by a flexible hinge. The two different positions observed for the terminal phosphate of the PLPP are interpreted as distinct phosphate subsites that may be occupied at different points along the reaction pathway. The structural basis for the unique ability of R-state dimers to form tetramers results from the orientation of subunits with respect to the dyad axis of the dimer. Residues in opposing dimers are in proper registration to form tetramers only in the R-state.

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“…4). The muscle form is the best characterized; both the primary sequence and the x-ray structure of rabbit muscle phosphorylase are known (5)(6)(7)(8). The enzyme functions in muscle to provide glucose required for the energy of contraction.…”

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confidence: 99%

Sequence analysis of the cDNA encoding human liver glycogen phosphorylase reveals tissue-specific codon usage.

Newgard¹,

Nakano²,

Hwang³

et al. 1986

Proc. Natl. Acad. Sci. U.S.A.

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We have cloned the cD)NA encoding glycogen phosphorylase (1,4-a-D-glucan:orthophosphate a-D-glucosyltransferase, EC 2.4.1.1) from human liver. Blot-hybridization analysis using a large fragment of the cDNA to probe mRNA from rabbit brain, muscle, and liver tissues shows preferential hybridization to liver RNA. Determination of the entire qucleotide sequence of the liver message has allowed a comparison with the previously determined rabbit muscle phosphorylase sequence. Despite an amino acid identity of 80%, the two cDNAs exhibit a remarkable divergence in G+C content. In the muscle phosphorylase sequence, 86% of the nucleotides at the third codon position are either deoxyguanosine or deoxycytidine residues, while in the liver homolog the figure is only 60%, resulting in a strikingly different pattern of codon usage throughout most of the sequence. The liver phosphorylase cDNA appears to represent an evolutionary mosaic; the segment encoding the N-terminal 80 amino acids contains >90% G+C at the third codon position. A survey of other published mammalian cDNA sequences reveals that the data for liver and muscle phosphorylases reflects a bias in codon usage patterns in liver and muscle coding sequences in general.Glycogen phosphorylase (1,4-a-D-glucan:orthophosphate a-D-glucosyltransferase, EC 2.4.1.1) isozymes play a vital role in mobilization of stored sugar in a variety of mammalian tissues. Three forms of the enzyme have been described that are distinguished by their electrophoretic mobilities on gels and their immunological properties (1-3). The three isozymes are tissue-specific; the brain type (also known as the fetal type) is predominant in adult brain and embryonic tissues, while the liver and muscle types are predominant in adult liver and skeletal muscle tissues, respectively (reviewed in ref. 4). The muscle form is the best characterized; both the primary sequence and the x-ray structure of rabbit muscle phosphorylase are known (5-8). The enzyme functions in muscle to provide glucose required for the energy of contraction. Its physiological role is distinct from the liver isozyme, which is centrally involved in the maintenance of blood glucose homeostasis, and from the brain form, which is associated primarily with provision of an emergency glucose supply during brief periods of anoxia or hypoglycemia (4, 9).Comparisons of the protein and DNA sequences of the phosphorylase isozymes are required to understand the evolutionary and functional relationships among them. Further, such comparisons could ultimately provide insight into how the phosphorylase genes, and perhaps other multigene families, are regulated in a developmental and tissue-specific manner. We have described the cloning and sequencing ofthe rabbit muscle glycogen phosphorylase cDNA and portions of the C-terminal domain from human and rat muscle (6, 7). We report here the cDNA sequence and the deduced amino acid sequence for human liver glycogen phosphorylase. Comparison of liver and muscle phosphorylase sequences reveals extensive...

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The Structures and Related Functions of Phosphorylase a

Cited by 205 publications

References 70 publications

Molecular cloning and sequencing of the glycogen phosphorylase gene from Escherichia coli

Molecular cloning and sequencing of the glycogen phosphorylase gene from Escherichia coli

Multiple phosphate positions in the catalytic site of glycogen phosphorylase: Structure of the pyridoxal‐5′‐pyrophosphate coenzyme‐substrate analog

Sequence analysis of the cDNA encoding human liver glycogen phosphorylase reveals tissue-specific codon usage.

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