DB code: S00709

RLCP classification	3.133.90030.334 : Transfer
CATH domain	3.90.550.10 : Spore Coat Polysaccharide Biosynthesis Protein SpsA; Chain A	Catalytic domain
E.C.	2.7.7.33
CSA
M-CSA
MACiE

CATH domain	Related DB codes (homologues)
3.90.550.10 : Spore Coat Polysaccharide Biosynthesis Protein SpsA; Chain A	S00465 S00466 D00417 D00859 D00860 T00415

Uniprot Enzyme Name
UniprotKB	Protein name	Synonyms	RefSeq	Pfam
Q8Z5I4		Glucose-1-phosphate cytidylyltransferase EC 2.7.7.33	NP_804622.1 (Protein) NC_004631.1 (DNA/RNA sequence)	PF00483 (NTP_transferase) [Graphical View]

KEGG enzyme name
Glucose-1-phosphate cytidylyltransferase CDP glucose pyrophosphorylase Cytidine diphosphoglucose pyrophosphorylase Cytidine diphosphate glucose pyrophosphorylase Cytidine diphosphate-D-glucose pyrophosphorylase CTP:D-glucose-1-phosphate cytidylyltransferase

UniprotKB: Accession Number	Entry name	Activity	Subunit	Subcellular location	Cofactor
Q8Z5I4	RFBF_SALTI	CTP + alpha-D-glucose 1-phosphate = diphosphate + CDP-glucose.	Homoexamer.		Binds 1 magnesium ion per subunit.

KEGG Pathways
Map code	Pathways	E.C.
MAP00500	Starch and sucrose metabolism
MAP00520	Nucleotide sugars metabolism

Compound table
	Cofactors	Substrates		Products		Intermediates
KEGG-id	C00305	C00063	C00103	C00013	C00501
E.C.
Compound	Magnesium	CTP	alpha-D-glucose 1-phosphate	diphosphate	CDP-glucose
Type	divalent metal (Ca2+, Mg2+)	amine group,nucleotide	carbohydrate,phosphate group/phosphate ion	phosphate group/phosphate ion	amide group,amine group,carbohydrate,nucleotide
ChEBI	18420 18420	17677 17677	29042 29042	29888 29888	28942 28942
PubChem	888 888	6176 6176	65533 65533	1023 21961011 1023 21961011	439244 439244

1tzfA00	Bound:_MG	Unbound	Unbound	Unbound	Bound:C5G
1wvcA00	Bound:2x_MG	Bound:CTP	Unbound	Unbound	Unbound

Reference for Active-site residues
resource	references	E.C.
literature [3], [5], [7]

Active-site residues
PDB	Catalytic residues	Cofactor-binding residues	Modified residues	Main-chain involved in catalysis	Comment

1tzfA00	;LYS 25;ARG 111;LYS 179	ASP 131;ASP 236(Magnesium binding)		LEU 12;GLY 13;	invisible 12-21
1wvcA00	ARG 15;LYS 25;ARG 111;	ASP 131;ASP 236(Magnesium binding)		LEU 12;GLY 13;THR 14	invisible 163, 178-179

References for Catalytic Mechanism
References	Sections	No. of steps in catalysis
[3]	Fig.1A, p.6657-6658
[5]	p.548-549
[6]	Fig. 3B, p.44027
[7]	Fig. 4, p10778-10780

References
[1]
Resource
Comments
Medline ID
PubMed ID	8276783
Journal	J Biol Chem
Year	1994
Volume	269
Pages	122-6
Authors	Lindqvist L, Kaiser R, Reeves PR, Lindberg AA
Title	Purification, characterization, and high performance liquid chromatography assay of Salmonella glucose-1-phosphate cytidylyltransferase from the cloned rfbF gene.
Related PDB
Related UniProtKB
[2]
Resource
Comments	X-RAY CRYSTALLOGRAPHY (2.25 ANGSTROMS) OF THE TRUNCATED FORM AND IN COMPLEX WITH UDP-GLCNAC
Medline ID
PubMed ID	10428949
Journal	EMBO J
Year	1999
Volume	18
Pages	4096-107
Authors	Brown K, Pompeo F, Dixon S, Mengin-Lecreulx D, Cambillau C, Bourne Y
Title	Crystal structure of the bifunctional N-acetylglucosamine 1-phosphate uridyltransferase from Escherichia coli: a paradigm for the related pyrophosphorylase superfamily.
Related PDB	1fwy 1fxj
Related UniProtKB	P0ACC7
[3]
Resource
Comments	X-RAY CRYSTALLOGRAPHY
Medline ID
PubMed ID	11118200
Journal	EMBO J
Year	2000
Volume	19
Pages	6652-63
Authors	Blankenfeldt W, Asuncion M, Lam JS, Naismith JH
Title	The structural basis of the catalytic mechanism and regulation of glucose-1-phosphate thymidylyltransferase (RmlA).
Related PDB	1fxo 1fzw 1g0r 1g1l 1g23 1g2v 1g3l
Related UniProtKB
[4]
Resource
Comments	CHARACTERIZATION, X-RAY CRYSTALLOGRAPHY (1.9 ANGSTROMS) OF COMPLEXES WITH DTDP-G; DTMP AND G1P AND DEOXYTHYMIDINE AND G1P
Medline ID
PubMed ID	11697907
Journal	J Mol Biol
Year	2001
Volume	313
Pages	831-43
Authors	Zuccotti S, Zanardi D, Rosano C, Sturla L, Tonetti M, Bolognesi M
Title	Kinetic and crystallographic analyses support a sequential-ordered bi bi catalytic mechanism for Escherichia coli glucose-1-phosphate thymidylyltransferase.
Related PDB	1h5r 1h5s 1h5t
Related UniProtKB	P37744
[5]
Resource
Comments	X-RAY CRYSTALLOGRAPHY (2.1 ANGSTROMS) OF 1-291
Medline ID
PubMed ID	11373625
Journal	Nat Struct Biol
Year	2001
Volume	8
Pages	545-51
Authors	Barton WA, Lesniak J, Biggins JB, Jeffrey PD, Jiang J, Rajashankar KR, Thorson JS, Nikolov DB
Title	Structure, mechanism and engineering of a nucleotidylyltransferase as a first step toward glycorandomization.
Related PDB	1iim 1iin
Related UniProtKB	Q9F7K6
[6]
Resource
Comments	X-RAY CRYSTALLOGRAPHY (2.1 ANGSTROMS)
Medline ID
PubMed ID	15292268
Journal	J Biol Chem
Year	2004
Volume	279
Pages	44023-9
Authors	Koropatkin NM, Holden HM
Title	Molecular structure of alpha-D-glucose-1-phosphate cytidylyltransferase from Salmonella typhi.
Related PDB	1tzf
Related UniProtKB
[7]
Resource
Comments	X-RAY CRYSTALLOGRAPHY (2.5 ANGSTROMS)
Medline ID
PubMed ID	15634670
Journal	J Biol Chem
Year	2005
Volume	280
Pages	10774-80
Authors	Koropatkin NM, Cleland WW, Holden HM
Title	Kinetic and structural analysis of alpha-D-Glucose-1-phosphate cytidylyltransferase from Salmonella typhi.
Related PDB	1wvc
Related UniProtKB
[8]
Resource
Comments
Medline ID
PubMed ID	16895327
Journal	Chem Rev
Year	2006
Volume	106
Pages	3252-78
Authors	Cleland WW, Hengge AC
Title	Enzymatic mechanisms of phosphate and sulfate transfer.
Related PDB
Related UniProtKB
[9]
Resource
Comments	X-RAY CRYSTALLOGRAPHY (2.0 ANGSTROMS)
Medline ID
PubMed ID	17567737
Journal	Protein Sci
Year	2007
Volume	16
Pages	1379-88
Authors	Thoden JB, Holden HM
Title	Active site geometry of glucose-1-phosphate uridylyltransferase.
Related PDB	2pa4
Related UniProtKB

Comments
This enzyme, Glucose-1-phosphate cytidylyltransferase (EC 2.7.7.33), is homologous to Glucose-1-phosphate thymidylyltransferase (EC 2.7.7.24; S00465 in EzCatDB). According to the literature [6[ and [7], the reaction proceeds as follows: (0) Sidechain of Arg15, along with mainchain amide groups of resideus Leu12, Gly13 and Thr14, and a magnesium bound to gamma-phosphate group, stabilize the negative charge on the leaving group, beta- and gamma-phosphate groups of CTP, whereas Lys25 and another magnesium ion which is bound to Asp131 and Asp236 may stabilize the negative charge on alpha-phosphate group of CTP. Meanwhile, Lys179 from adjacent subunit may stabilize the phosphate group of Glucose 1-phosphate. (1) The phosphoryl oxygen of Glucose 1-phosphate makes a nucleophilic attack on the alpha-phosphate group of CTP, leading to the transition-state (SN2-like reaction). (2) The transition-state must be stabilized by sidechains of Arg15, Lys25 and Lys179, mainchain amide groups of residues 12 to 14, and the two magnesium ions bound to phosphate groups of CTP. (3) Finally, diphosphate is released from CTP, forming CDP-glucose.

Comments

This enzyme, Glucose-1-phosphate cytidylyltransferase (EC 2.7.7.33), is homologous to Glucose-1-phosphate thymidylyltransferase (EC 2.7.7.24; S00465 in EzCatDB).
According to the literature [6[ and [7], the reaction proceeds as follows:
(0) Sidechain of Arg15, along with mainchain amide groups of resideus Leu12, Gly13 and Thr14, and a magnesium bound to gamma-phosphate group, stabilize the negative charge on the leaving group, beta- and gamma-phosphate groups of CTP, whereas Lys25 and another magnesium ion which is bound to Asp131 and Asp236 may stabilize the negative charge on alpha-phosphate group of CTP. Meanwhile, Lys179 from adjacent subunit may stabilize the phosphate group of Glucose 1-phosphate.
(1) The phosphoryl oxygen of Glucose 1-phosphate makes a nucleophilic attack on the alpha-phosphate group of CTP, leading to the transition-state (SN2-like reaction).
(2) The transition-state must be stabilized by sidechains of Arg15, Lys25 and Lys179, mainchain amide groups of residues 12 to 14, and the two magnesium ions bound to phosphate groups of CTP.
(3) Finally, diphosphate is released from CTP, forming CDP-glucose.

Created	Updated
2009-03-31	2011-12-02