“Adenylosuccinate synthase”的意思、由来-开放百科全书

词条

Adenylosuccinate synthase

释义

Structure
Isozymes
External links
References

{{enzyme
| Name = Adenylosuccinate synthase
| EC_number = 6.3.4.4
| CAS_number = 9023-57-8
| IUBMB_EC_number = 6/3/4/4
| GO_code = 0004019
| image = 2v40.jpg
| width = 270
| caption = Adenylosuccinate synthetase dimer, Human
}}{{Infobox protein family
| Symbol = Adenylsucc_synt
| Name = Adenylsucc_synt
| image = PDB 1dj3 EBI.jpg
| width =
| caption = structures of adenylosuccinate synthetase from triticum aestivum and arabidopsis thaliana
| Pfam = PF00709
| Pfam_clan = CL0023
| InterPro = IPR001114
| SMART =
| PROSITE = PDOC00444
| MEROPS =
| SCOP = 1ade
| TCDB =
| OPM family =
| OPM protein =
| CAZy =
| CDD =
}}

In molecular biology, Adenylosuccinate synthase (or adenylosuccinate synthetase) ({{EC number|6.3.4.4.}}) is an enzyme that plays an important role in purine biosynthesis, by catalysing the guanosine triphosphate (GTP)-dependent conversion of inosine monophosphate (IMP) and aspartic acid to guanosine diphosphate (GDP), phosphate and N(6)-(1,2-dicarboxyethyl)-AMP. Adenylosuccinate synthetase has been characterised from various sources ranging from Escherichia coli (gene purA) to vertebrate tissues. In vertebrates, two isozymes are present: one involved in purine biosynthesis and the other in the purine nucleotide cycle.

Structure

The crystal structure of adenylosuccinate synthetase from E. coli reveals that the dominant structural element of each monomer of the homodimer is a central beta-sheet of 10 strands. The first nine strands of the sheet are mutually parallel with right-handed crossover connections between the strands. The 10th strand is antiparallel with respect to the first nine strands. In addition, the enzyme has two antiparallel beta-sheets, composed of two strands and three strands each, 11 alpha-helices and two short 3/10-helices. Further, it has been suggested that the similarities in the GTP-binding domains of the synthetase and the p21ras protein are an example of convergent evolution of two distinct families of GTP-binding proteins.^[1] Structures of adenylosuccinate synthetase from Triticum aestivum and Arabidopsis thaliana when compared with the known structures from E. coli reveals that the overall fold is very similar to that of the E. coli protein.^[2]

Isozymes

Humans express two adenylosuccinate synthase isozymes:

{{infobox protein

Name = adenylosuccinate synthase

caption =

image =

width =

HGNCid = 292

Symbol = ADSS

AltSymbols =

EntrezGene = 159

OMIM = 103060

RefSeq = NM_001126

UniProt = P30520

PDB =

ECnumber = 6.3.4.4

Chromosome = 1

Arm = q

Band = 44

LocusSupplementaryData =
}}

{{infobox protein

Name = adenylosuccinate synthase like 1

caption =

image =

width =

HGNCid = 20093

Symbol = ADSSL1

AltSymbols =

EntrezGene = 122622

OMIM = 612498

RefSeq = NM_152328

UniProt = Q8N142

PDB =

ECnumber = 6.3.4.4

Chromosome = 14

Arm = q

Band = 32.33

LocusSupplementaryData =
}}

External links

{{MeshName|Adenylosuccinate+synthase}}

References

1. ^{{cite journal | vauthors = Poland BW, Silva MM, Serra MA, Cho Y, Kim KH, Harris EM, Honzatko RB | title = Crystal structure of adenylosuccinate synthetase from Escherichia coli. Evidence for convergent evolution of GTP-binding domains | journal = J. Biol. Chem. | volume = 268 | issue = 34 | pages = 25334–42 |date=December 1993| pmid = 8244965 | doi = | url = }}
2. ^{{cite journal | vauthors = Prade L, Cowan-Jacob SW, Chemla P, Potter S, Ward E, Fonne-Pfister R | title = Structures of adenylosuccinate synthetase from Triticum aestivum and Arabidopsis thaliana | journal = J. Mol. Biol. | volume = 296 | issue = 2 | pages = 569–77 |date=February 2000| pmid = 10669609 | doi = 10.1006/jmbi.1999.3473 | url = }}

{{InterPro content|IPR001114}}{{Nucleotide metabolism}}{{Ligases CO CS and CN}}{{Enzymes}}{{Portal bar|Molecular and Cellular Biology|border=no}}

1 : EC 6.3.4

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