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discounted EARLY registration ends Dec 31, 2014
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Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
BioCyc websites down
12/28 - 12/31
for maintenance.
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
BioCyc websites down
12/28 - 12/31
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discounted EARLY registration ends Dec 31, 2014
BioCyc websites down
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MetaCyc Enzyme: inositol monophosphatase

Gene: suhB Accession Numbers: EG10983 (MetaCyc), b2533, ECK2530

Synonyms: ssyA

Species: Escherichia coli K-12 substr. MG1655

Summary:
The suhB gene has been shown to encode a protein with inositol monophosphatase and glycerol-2-phosphatase activity [Matsuhisa95]. However, inositol monophosphatase activity appears to be neither sufficient nor necessary for rescue of the cold-sensitive growth phenotype of an suhB mutant [Chen00]. Thus, the physiological role of the enzyme is not fully understood.

The protein exists as a mixture of monomers and dimers in solution. The monomeric form can interact with RNA polymerase, and the ability of mutants to bind to RNA polymerase correlates with their ability to rescue the cold-sensitive growth defect of an suhB mutant [Wang07c]. The crystal structure of a point mutant of SuhB that forms dimers has been solved [Wang07c].

suhB was initially identified as a suppressor of a secY mutant [Shiba84], an rpoH mutant [Yano90], and a dnaB mutant [Chang91a]. The protein products of these genes are involved in protein export, the heat shock response, and DNA replication, respectively. In all cases, the suhB suppressor allele causes a cold-sensitive growth phenotype. Suppressors of the cold-sensitive phenotype of an suhB suppressor allele map to rnc, which encodes RNase III [Inada95]. Expression of suhB appears to be autoregulated at the level of mRNA stability [Inada96].

SsyA: "suppressor of secY24" [Shiba84]

SuhB: "suppressor of rpoH15 [Yano90]

Locations: cytosol

Map Position: [2,661,464 -> 2,662,267]

Molecular Weight of Polypeptide: 29.172 kD (from nucleotide sequence), 30.0 kD (experimental) [Chang91a ]

Unification Links: ASAP:ABE-0008337 , CGSC:32968 , EchoBASE:EB0976 , EcoGene:EG10983 , EcoliWiki:b2533 , ModBase:P0ADG4 , OU-Microarray:b2533 , PortEco:suhB , PR:PRO_000024012 , Pride:P0ADG4 , Protein Model Portal:P0ADG4 , RefSeq:NP_417028 , RegulonDB:EG10983 , SMR:P0ADG4 , String:511145.b2533 , UniProt:P0ADG4

Relationship Links: InterPro:IN-FAMILY:IPR000760 , InterPro:IN-FAMILY:IPR020550 , InterPro:IN-FAMILY:IPR020583 , InterPro:IN-FAMILY:IPR022337 , Panther:IN-FAMILY:PTHR20854 , PDB:Structure:2QFL , Pfam:IN-FAMILY:PF00459 , Prints:IN-FAMILY:PR00377 , Prints:IN-FAMILY:PR01959 , Prosite:IN-FAMILY:PS00629 , Prosite:IN-FAMILY:PS00630

Gene-Reaction Schematic: ?

GO Terms:

Biological Process: GO:0046855 - inositol phosphate dephosphorylation Inferred from experiment Inferred by computational analysis [GOA01a, Chen00]
GO:0046854 - phosphatidylinositol phosphorylation Inferred by computational analysis [GOA01a]
Molecular Function: GO:0000287 - magnesium ion binding Inferred from experiment [Chen00, Matsuhisa95]
GO:0008934 - inositol monophosphate 1-phosphatase activity Inferred from experiment Inferred by computational analysis [GOA01, GOA01a, Chen00, Matsuhisa95]
GO:0031403 - lithium ion binding Inferred from experiment [Chen00]
GO:0043175 - RNA polymerase core enzyme binding Inferred from experiment [Wang07c]
GO:0047954 - glycerol-2-phosphatase activity Inferred from experiment [Matsuhisa95]
GO:0016787 - hydrolase activity Inferred by computational analysis [UniProtGOA11a]
GO:0046872 - metal ion binding Inferred by computational analysis [UniProtGOA11a]
GO:0052832 - inositol monophosphate 3-phosphatase activity Inferred by computational analysis [GOA01]
GO:0052833 - inositol monophosphate 4-phosphatase activity Inferred by computational analysis [GOA01]
Cellular Component: GO:0005737 - cytoplasm Inferred from experiment [Chen00]
GO:0005829 - cytosol Inferred from experiment Inferred by computational analysis [DiazMejia09, Ishihama08, LopezCampistrou05]

MultiFun Terms: regulation type of regulation posttranscriptional

Credits:
Imported from EcoCyc 16-Sep-2014 by Paley S , SRI International


Enzymatic reaction of: glycerol-2-phosphatase (inositol monophosphatase)

Synonyms: glycerol-2-phosphate phosphohydrolase, β-glycerophosphatase

EC Number: 3.1.3.19

glycerol 2-phosphate + H2O <=> glycerol + phosphate

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.

The reaction is physiologically favored in the direction shown.

Credits:
Imported from EcoCyc 16-Sep-2014 by Paley S , SRI International

Cofactors or Prosthetic Groups: Mg2+ [Matsuhisa95]


Enzymatic reaction of: inositol monophosphatase

Synonyms: myo-inositol-1(or 4)-monophosphatase, myo-inositol-1(or 4)-phosphate phosphohydrolase

1D-myo-inositol 1-monophosphate + H2O <=> myo-inositol + phosphate

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.

The reaction is physiologically favored in the direction shown.

Alternative Substrates for 1D-myo-inositol 1-monophosphate: 1D-myo-inositol 2-monophosphate [Matsuhisa95 ] , glycerol 2-phosphate [Matsuhisa95 ]

Credits:
Imported from EcoCyc 16-Sep-2014 by Paley S , SRI International

Summary:
In contrast to the mammalian enzyme (which does not hydrolyze myo-inositol 2-monophosphate at all), SuhB hydrolyzes myo-inositol 2-monophosphate with about 77% of activity compared to myo-inositol 1-monophosphate [Matsuhisa95].

Cofactors or Prosthetic Groups: Mg2+ [Comment 1, Chen00, Matsuhisa95]

Inhibitors (Unknown Mechanism): Li+ [Matsuhisa95, Chen00, Comment 2]

Kinetic Parameters:

Substrate
Km (μM)
Citations
1D-myo-inositol 1-monophosphate
64.0
[Chen00]

pH(opt): 7.8 [Matsuhisa95]


Sequence Features

Feature Class Location Citations Comment
Metal-Binding-Site 67
[UniProt10]
UniProt: Magnesium 1; Non-Experimental Qualifier: by similarity;
Metal-Binding-Site 84
[UniProt10]
UniProt: Magnesium 1; Non-Experimental Qualifier: by similarity;
Metal-Binding-Site 86
[UniProt10]
UniProt: Magnesium 1; via carbonyl oxygen; Non-Experimental Qualifier: by similarity;
Protein-Segment 86 -> 89
[UniProt10]
UniProt: Substrate binding; Sequence Annotation Type: region of interest; Non-Experimental Qualifier: by similarity;
Metal-Binding-Site 87
[UniProt10]
UniProt: Magnesium 2; Non-Experimental Qualifier: by similarity;
Sequence-Conflict 141
[Yano90, UniProt10a]
Alternate sequence: L; UniProt: (in Ref. 1; AAA67506);
Amino-Acid-Sites-That-Bind 183
[UniProt10]
UniProt: Substrate; Non-Experimental Qualifier: by similarity;
Metal-Binding-Site 212
[UniProt10]
UniProt: Magnesium 2; Non-Experimental Qualifier: by similarity;

History:
3/2/1998 (pkarp) Merged genes G478/b2533 and EG10983/suhB
10/20/97 Gene b2533 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG10983; confirmed by SwissProt match.


References

Chang91a: Chang SF, Ng D, Baird L, Georgopoulos C (1991). "Analysis of an Escherichia coli dnaB temperature-sensitive insertion mutation and its cold-sensitive extragenic suppressor." J Biol Chem 266(6);3654-60. PMID: 1847383

Chen00: Chen L, Roberts MF (2000). "Overexpression, purification, and analysis of complementation behavior of E. coli SuhB protein: comparison with bacterial and archaeal inositol monophosphatases." Biochemistry 2000;39(14);4145-53. PMID: 10747806

DiazMejia09: Diaz-Mejia JJ, Babu M, Emili A (2009). "Computational and experimental approaches to chart the Escherichia coli cell-envelope-associated proteome and interactome." FEMS Microbiol Rev 33(1);66-97. PMID: 19054114

GOA01: GOA, MGI (2001). "Gene Ontology annotation based on Enzyme Commission mapping." Genomics 74;121-128.

GOA01a: GOA, DDB, FB, MGI, ZFIN (2001). "Gene Ontology annotation through association of InterPro records with GO terms."

Inada95: Inada T, Nakamura Y (1995). "Lethal double-stranded RNA processing activity of ribonuclease III in the absence of suhB protein of Escherichia coli." Biochimie 77(4);294-302. PMID: 8589060

Inada96: Inada T, Nakamura Y (1996). "Autogenous control of the suhB gene expression of Escherichia coli." Biochimie 78(3);209-12. PMID: 8831954

Ishihama08: Ishihama Y, Schmidt T, Rappsilber J, Mann M, Hartl FU, Kerner MJ, Frishman D (2008). "Protein abundance profiling of the Escherichia coli cytosol." BMC Genomics 9;102. PMID: 18304323

LopezCampistrou05: Lopez-Campistrous A, Semchuk P, Burke L, Palmer-Stone T, Brokx SJ, Broderick G, Bottorff D, Bolch S, Weiner JH, Ellison MJ (2005). "Localization, annotation, and comparison of the Escherichia coli K-12 proteome under two states of growth." Mol Cell Proteomics 4(8);1205-9. PMID: 15911532

Matsuhisa95: Matsuhisa A, Suzuki N, Noda T, Shiba K (1995). "Inositol monophosphatase activity from the Escherichia coli suhB gene product." J Bacteriol 1995;177(1);200-5. PMID: 8002619

Shiba84: Shiba K, Ito K, Yura T (1984). "Mutation that suppresses the protein export defect of the secY mutation and causes cold-sensitive growth of Escherichia coli." J Bacteriol 160(2);696-701. PMID: 6389495

UniProt10: UniProt Consortium (2010). "UniProt version 2010-07 released on 2010-06-15 00:00:00." Database.

UniProt10a: UniProt Consortium (2010). "UniProt version 2010-11 released on 2010-11-02 00:00:00." Database.

UniProtGOA11a: UniProt-GOA (2011). "Gene Ontology annotation based on manual assignment of UniProtKB keywords in UniProtKB/Swiss-Prot entries."

Wang07c: Wang Y, Stieglitz KA, Bubunenko M, Court DL, Stec B, Roberts MF (2007). "The structure of the R184A mutant of the inositol monophosphatase encoded by suhB and implications for its functional interactions in Escherichia coli." J Biol Chem 282(37);26989-96. PMID: 17652087

Yano90: Yano R, Nagai H, Shiba K, Yura T (1990). "A mutation that enhances synthesis of sigma 32 and suppresses temperature-sensitive growth of the rpoH15 mutant of Escherichia coli." J Bacteriol 172(4);2124-30. PMID: 2138605


Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by SRI International Pathway Tools version 18.5 on Sat Dec 20, 2014, BIOCYC13B.