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Escherichia coli K-12 substr. MG1655 Enzyme: glutamyl-tRNA reductase



Gene: hemA Accession Numbers: EG10427 (EcoCyc), b1210, ECK1198

Synonyms: gtrA

Regulation Summary Diagram: ?

Subunit composition of glutamyl-tRNA reductase = [HemA]2

Summary:
Glutamyl-tRNA reductase catalyzes the first step of porphyrin biosynthesis. The reaction appears to proceed via a thioester intermediate [Schauer02]. Determinants for recognition of Glu-tRNA(Glu) by the enzyme have been studied [Randau04]. HemA can be isolated in multiple multimeric forms, but the dimer may represent the functional form of the enzyme [Schauer02]. The HemA dimer forms a tight complex with glutamate-1-semialdehyde 2,1-aminomutase, the second enzyme in the pathway, suggesting metabolic channeling of the highly reactive intermediate glutamate-1-semialdehyde [Luer05].

Heme limitation leads to an increase in abundance of HemA protein [Wang97b], although only a 3-fold increase in hemA expression can be detected [McNicholas97a]. In Salmonella typhimurium, HemA abundance appears to be increased by stabilization of the protein [Wang99a].

Mutants of hemA are dependent on δ-aminolevulinic acid (ALA) for growth and can not produce ALA from either glutamate or glutamyl-tRNA [Sasarman68, Avissar89].

Gene Citations: [Verkamp89, Dahlgren04]

Locations: cytosol

Map Position: [1,262,937 -> 1,264,193] (27.22 centisomes)
Length: 1257 bp / 418 aa

Molecular Weight of Polypeptide: 46.307 kD (from nucleotide sequence), 46 kD (experimental) [Drolet89 ]

Molecular Weight of Multimer: 85.0 kD (experimental) [Jahn91]

pI: 5.7

Unification Links: ASAP:ABE-0004064 , CGSC:648 , EchoBASE:EB0422 , EcoGene:EG10427 , EcoliWiki:b1210 , ModBase:P0A6X1 , OU-Microarray:b1210 , PortEco:hemA , PR:PRO_000022874 , Pride:P0A6X1 , Protein Model Portal:P0A6X1 , RefSeq:NP_415728 , RegulonDB:EG10427 , SMR:P0A6X1 , String:511145.b1210 , UniProt:P0A6X1

Relationship Links: InterPro:IN-FAMILY:IPR000343 , InterPro:IN-FAMILY:IPR006151 , InterPro:IN-FAMILY:IPR015895 , InterPro:IN-FAMILY:IPR015896 , InterPro:IN-FAMILY:IPR016040 , InterPro:IN-FAMILY:IPR018214 , Pfam:IN-FAMILY:PF00745 , Pfam:IN-FAMILY:PF01488 , Pfam:IN-FAMILY:PF05201 , Prosite:IN-FAMILY:PS00747

Gene-Reaction Schematic: ?

Genetic Regulation Schematic: ?

GO Terms:

Biological Process: GO:0019353 - protoporphyrinogen IX biosynthetic process from glutamate Inferred from experiment [Miyamoto92]
GO:0006779 - porphyrin-containing compound biosynthetic process Inferred by computational analysis [UniProtGOA11, GOA06]
GO:0006782 - protoporphyrinogen IX biosynthetic process Inferred by computational analysis [UniProtGOA12]
GO:0033014 - tetrapyrrole biosynthetic process Inferred by computational analysis [GOA01]
GO:0055114 - oxidation-reduction process Inferred by computational analysis [UniProtGOA11, GOA01]
Molecular Function: GO:0005515 - protein binding Inferred from experiment [Luer05]
GO:0008883 - glutamyl-tRNA reductase activity Inferred from experiment Inferred by computational analysis [GOA06, GOA01a, GOA01, Schauer02]
GO:0042802 - identical protein binding Inferred from experiment [Jahn91]
GO:0016491 - oxidoreductase activity Inferred by computational analysis [UniProtGOA11]
GO:0050661 - NADP binding Inferred by computational analysis [GOA01]
Cellular Component: GO:0005829 - cytosol Inferred by computational analysis [DiazMejia09]

MultiFun Terms: metabolism biosynthesis of building blocks cofactors, small molecule carriers heme, porphyrine

Essentiality data for hemA knockouts: ?

Growth Medium Growth? T (°C) O2 pH Osm/L Growth Observations
LB Lennox No 37 Aerobic 7   No [Baba06, Comment 1]

Credits:
Last-Curated ? 31-May-2013 by Kubo A , SRI International


Enzymatic reaction of: glutamyl-tRNA reductase

Synonyms: GluTR, glutamyl-tRNA reductase, GTR

EC Number: 1.2.1.70

glutamate-1-semialdehyde + tRNAGlu + NADP+ <=> L-glutamyl-tRNAGlu + NADPH

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 favored in the opposite direction.

In Pathways: tetrapyrrole biosynthesis I (from glutamate)

Summary:
E. coli was reported to have two distinct glutamyl-tRNA reductase (GluTR) activities, one with a size of 85 KDa (GluTR85) and the other 45 KDa (GluTR45) [Jahn91]. The hemA gene has been shown to code for the GluTR45 activity [Verkamp92]. Later, it was shown that HemA can be isolated in multiple multimeric forms, but the dimer may represent the functional form of the enzyme [Schauer02].

Kinetic Parameters:

Substrate
Km (μM)
kcat (sec-1)
kcat/Km (sec-1 μM-1)
Citations
NADPH
39.0
0.15
[Schauer02, BRENDA14]
L-glutamyl-tRNAGlu
24.0
0.13
[Schauer02, BRENDA14]

T(opt): 37 °C [BRENDA14, Schauer03]

pH(opt): 8.1 [BRENDA14, Schauer03]


Sequence Features

Feature Class Location Citations Comment
Mutagenesis-Variant 7
[Schauer02, UniProt11]
Alternate sequence: G → D; UniProt: Loss of activity.
Mutagenesis-Variant 49
[Luer07, UniProt11]
Alternate sequence: T → V; UniProt: 10% and 5% of wild-type reductase and esterase activity, respectively.
Protein-Segment 49 -> 52
[UniProt10]
UniProt: Substrate binding; Sequence Annotation Type: region of interest; Non-Experimental Qualifier: probable;
Mutagenesis-Variant 50
[Schauer02, UniProt11]
Alternate sequence: C → S; UniProt: Loss of activity.
Active-Site 50
[UniProt10a]
UniProt: Nucleophile;
Mutagenesis-Variant 52
[Luer07, UniProt11]
Alternate sequence: R → Q; UniProt: Loss of activity.
Alternate sequence: R → K; UniProt: 5% and 4% of wild-type reductase and esterase activity, respectively.
Mutagenesis-Variant 54
[Luer07, UniProt11]
Alternate sequence: E → K; UniProt: 6% and 2% of wild-type reductase and esterase activity, respectively.
Mutagenesis-Variant 74
[Schauer02, UniProt11]
Alternate sequence: C → S; UniProt: No effect.
Mutagenesis-Variant 99
[Luer07, UniProt11]
Alternate sequence: H → N; UniProt: 5% and 4% of wild-type reductase and esterase activity, respectively.
Amino-Acid-Site 99
[UniProt10a]
UniProt: Important for activity; Sequence Annotation Type: site;
Mutagenesis-Variant 106
[Schauer02, UniProt11]
Alternate sequence: G → N; UniProt: Loss of activity.
Mutagenesis-Variant 109
[Luer07, UniProt11]
Alternate sequence: S → A; UniProt: 28% and 25% of wild-type reductase and esterase activity, respectively.
Amino-Acid-Sites-That-Bind 109
[UniProt10]
UniProt: Substrate; Non-Experimental Qualifier: probable;
Mutagenesis-Variant 114
[Schauer02, UniProt11]
Alternate sequence: E → K; UniProt: Loss of activity.
Protein-Segment 114 -> 116
[UniProt10]
UniProt: Substrate binding; Sequence Annotation Type: region of interest; Non-Experimental Qualifier: probable;
Mutagenesis-Variant 116
[Luer07, UniProt11]
Alternate sequence: Q → L; UniProt: Loss of reductase activity. 30% of wild-type esterase activity.
Amino-Acid-Sites-That-Bind 120
[UniProt10]
UniProt: Substrate; Non-Experimental Qualifier: by similarity;
Mutagenesis-Variant 145
[Schauer02, UniProt11]
Alternate sequence: S → F; UniProt: Loss of activity.
Sequence-Conflict 151 -> 168
[Drolet89, UniProt10a]
Alternate sequence: RVRTETDIGASAVSVAFA → PFALKQISVPALCLSLLP; UniProt: (in Ref. 3; CAA35476);
Mutagenesis-Variant 170
[Schauer02, UniProt11]
Alternate sequence: C → S; UniProt: No effect.
Sequence-Conflict 172
[Drolet89, UniProt10a]
Alternate sequence: L → V; UniProt: (in Ref. 3; CAA35476);
Nucleotide-Phosphate-Binding-Region 189 -> 194
[UniProt10]
UniProt: NADP; Non-Experimental Qualifier: probable;
Mutagenesis-Variant 191
[Schauer02, UniProt11]
Alternate sequence: G → D; UniProt: Loss of reductase activity. Retains esterase activity.
Sequence-Conflict 240
[Drolet89, UniProt10a]
Alternate sequence: L → M; UniProt: (in Ref. 3; CAA35476);
Sequence-Conflict 243
[Li89, Strohmaier95, UniProt10a]
Alternate sequence: A → R; UniProt: (in Ref. 1 and 4);
Mutagenesis-Variant 314
[Schauer02, UniProt11]
Alternate sequence: R → C; UniProt: Loss of activity.
Sequence-Conflict 365
[Drolet89, UniProt10a]
Alternate sequence: A → R; UniProt: (in Ref. 3; CAA35476);


Gene Local Context (not to scale): ?

Transcription Units:

Notes:

History:
10/20/97 Gene b1210 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG10427; confirmed by SwissProt match.


References

Avissar89: Avissar YJ, Beale SI (1989). "Identification of the enzymatic basis for delta-aminolevulinic acid auxotrophy in a hemA mutant of Escherichia coli." J Bacteriol 171(6);2919-24. PMID: 2656630

Baba06: Baba T, Ara T, Hasegawa M, Takai Y, Okumura Y, Baba M, Datsenko KA, Tomita M, Wanner BL, Mori H (2006). "Construction of Escherichia coli K-12 in-frame, single-gene knockout mutants: the Keio collection." Mol Syst Biol 2;2006.0008. PMID: 16738554

BRENDA14: BRENDA team (2014). "Imported from BRENDA version existing on Aug 2014." http://www.brenda-enzymes.org.

Dahlgren04: Dahlgren A, Ryden-Aulin M (2004). "Effects of two cis-acting mutations on the regulation and expression of release factor one in Escherichia coli." Biochimie 86(7);431-8. PMID: 15308332

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

Drolet89: Drolet M, Peloquin L, Echelard Y, Cousineau L, Sasarman A (1989). "Isolation and nucleotide sequence of the hemA gene of Escherichia coli K12." Mol Gen Genet 216(2-3);347-52. PMID: 2664455

GOA01: GOA, DDB, FB, MGI, ZFIN (2001). "Gene Ontology annotation through association of InterPro records with GO terms."

GOA01a: GOA, MGI (2001). "Gene Ontology annotation based on Enzyme Commission mapping." Genomics 74;121-128.

GOA06: GOA, SIB (2006). "Electronic Gene Ontology annotations created by transferring manual GO annotations between orthologous microbial proteins."

Jahn91: Jahn D, Michelsen U, Soll D (1991). "Two glutamyl-tRNA reductase activities in Escherichia coli." J Biol Chem 266(4);2542-8. PMID: 1990004

Li89: Li JM, Russell CS, Cosloy SD (1989). "Cloning and structure of the hem A gene of Escherichia coli K-12." Gene 82(2);209-17. PMID: 2684779

Luer05: Luer C, Schauer S, Mobius K, Schulze J, Schubert WD, Heinz DW, Jahn D, Moser J (2005). "Complex formation between glutamyl-tRNA reductase and glutamate-1-semialdehyde 2,1-aminomutase in Escherichia coli during the initial reactions of porphyrin biosynthesis." J Biol Chem 280(19);18568-72. PMID: 15757895

Luer07: Luer C, Schauer S, Virus S, Schubert WD, Heinz DW, Moser J, Jahn D (2007). "Glutamate recognition and hydride transfer by Escherichia coli glutamyl-tRNA reductase." FEBS J 274(17);4609-14. PMID: 17697121

McNicholas97a: McNicholas PM, Javor G, Darie S, Gunsalus RP (1997). "Expression of the heme biosynthetic pathway genes hemCD, hemH, hemM, and hemA of Escherichia coli." FEMS Microbiol Lett 146(1);143-8. PMID: 8997718

Miyamoto92: Miyamoto K, Nishimura K, Masuda T, Tsuji H, Inokuchi H (1992). "Accumulation of protoporphyrin IX in light-sensitive mutants of Escherichia coli." FEBS Lett 310(3);246-8. PMID: 1397280

Randau04: Randau L, Schauer S, Ambrogelly A, Salazar JC, Moser J, Sekine S, Yokoyama S, Soll D, Jahn D (2004). "tRNA recognition by glutamyl-tRNA reductase." J Biol Chem 279(33);34931-7. PMID: 15194701

Sasarman68: Sasarman A, Surdeanu M, Szegli G, Horodniceanu T, Greceanu V, Dumitrescu A (1968). "Hemin-deficient mutants of Escherichia coli K-12." J Bacteriol 96(2);570-2. PMID: 4877132

Schauer02: Schauer S, Chaturvedi S, Randau L, Moser J, Kitabatake M, Lorenz S, Verkamp E, Schubert WD, Nakayashiki T, Murai M, Wall K, Thomann HU, Heinz DW, Inokuchi H, Soll D, Jahn D (2002). "Escherichia coli glutamyl-tRNA reductase. Trapping the thioester intermediate." J Biol Chem 277(50);48657-63. PMID: 12370189

Schauer03: Schauer S, Luer C, Moser J (2003). "Large scale production of biologically active Escherichia coli glutamyl-tRNA reductase from inclusion bodies." Protein Expr Purif 31(2);271-5. PMID: 14550647

Strohmaier95: Strohmaier H, Remler P, Renner W, Hogenauer G (1995). "Expression of genes kdsA and kdsB involved in 3-deoxy-D-manno-octulosonic acid metabolism and biosynthesis of enterobacterial lipopolysaccharide is growth phase regulated primarily at the transcriptional level in Escherichia coli K-12." J Bacteriol 177(15);4488-500. PMID: 7543480

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.

UniProt11: UniProt Consortium (2011). "UniProt version 2011-06 released on 2011-06-30 00:00:00." Database.

UniProtGOA11: UniProt-GOA (2011). "Gene Ontology annotation based on manual assignment of UniProtKB keywords in UniProtKB/Swiss-Prot entries."

UniProtGOA12: UniProt-GOA (2012). "Gene Ontology annotation based on UniPathway vocabulary mapping."

Verkamp89: Verkamp E, Chelm BK (1989). "Isolation, nucleotide sequence, and preliminary characterization of the Escherichia coli K-12 hemA gene." J Bacteriol 171(9);4728-35. PMID: 2548996

Verkamp92: Verkamp E, Jahn M, Jahn D, Kumar AM, Soll D (1992). "Glutamyl-tRNA reductase from Escherichia coli and Synechocystis 6803. Gene structure and expression." J Biol Chem 1992;267(12);8275-80. PMID: 1569081

Wang97b: Wang LY, Brown L, Elliott M, Elliott T (1997). "Regulation of heme biosynthesis in Salmonella typhimurium: activity of glutamyl-tRNA reductase (HemA) is greatly elevated during heme limitation by a mechanism which increases abundance of the protein." J Bacteriol 179(9);2907-14. PMID: 9139907

Wang99a: Wang L, Elliott M, Elliott T (1999). "Conditional stability of the HemA protein (glutamyl-tRNA reductase) regulates heme biosynthesis in Salmonella typhimurium." J Bacteriol 181(4);1211-9. PMID: 9973348

Other References Related to Gene Regulation

Choi96: Choi P, Wang L, Archer CD, Elliott T (1996). "Transcription of the glutamyl-tRNA reductase (hemA) gene in Salmonella typhimurium and Escherichia coli: role of the hemA P1 promoter and the arcA gene product." J Bacteriol 1996;178(3);638-46. PMID: 8550494

Darie94: Darie S, Gunsalus RP (1994). "Effect of heme and oxygen availability on hemA gene expression in Escherichia coli: role of the fnr, arcA, and himA gene products." J Bacteriol 1994;176(17);5270-6. PMID: 8071201

Melville96: Melville SB, Gunsalus RP (1996). "Isolation of an oxygen-sensitive FNR protein of Escherichia coli: interaction at activator and repressor sites of FNR-controlled genes." Proc Natl Acad Sci U S A 93(3);1226-31. PMID: 8577745


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Please cite the following article in publications resulting from the use of EcoCyc: Nucleic Acids Research 41:D605-12 2013
Page generated by SRI International Pathway Tools version 18.5 on Wed Nov 26, 2014, biocyc13.