Escherichia coli K-12 substr. MG1655 Enzyme: glutamate-1-semialdehyde aminotransferase

Gene: hemL Accession Numbers: EG10432 (EcoCyc), b0154, ECK0153

Synonyms: gsa, popC

Regulation Summary Diagram: ?

Regulation summary diagram for hemL

Subunit composition of glutamate-1-semialdehyde aminotransferase = [HemL]2
         glutamate-1-semialdehyde aminotransferase = HemL

Glutamate-1-semialdehyde aminotransferase (GSA-T) catalyzes the pyridoxal 5'-phosphate-dependent reaction which converts glutamate-1-semialdehyde (GSA) to δ-aminolevulinate (ALA). ALA is the first committed precursor of porphyrin biosynthesis [Ilag91]. The enzyme is homodimeric [Ilag91].

HemL forms a tight complex with glytamyl-tRNA reductase, the preceding enzyme in the pathway, suggesting metabolic channeling of the highly reactive intermediate GSA [Luer05].

Transcription of hemL is regulated by Mg2+ and PhoP [Minagawa03].

hemL is one of a network of genes believed to play a role in promoting the stress-induced mutagenesis (SIM) response [Al12].

Mutants of hemL have demonstrated loss of GSA-T function and leaky ALA auxotrophy [Ilag92].

Locations: cytosol

Map Position: [173,602 <- 174,882] (3.74 centisomes, 13°)
Length: 1281 bp / 426 aa

Molecular Weight of Polypeptide: 45.366 kD (from nucleotide sequence), 40 kD (experimental) [Ilag91 ]

Molecular Weight of Multimer: 80 kD (experimental) [Ilag91]

pI: 4.99

Unification Links: ASAP:ABE-0000529 , CGSC:372 , DIP:DIP-9886N , EchoBASE:EB0427 , EcoGene:EG10432 , EcoliWiki:b0154 , ModBase:P23893 , OU-Microarray:b0154 , PortEco:hemL , PR:PRO_000022878 , Pride:P23893 , Protein Model Portal:P23893 , RefSeq:NP_414696 , RegulonDB:EG10432 , SMR:P23893 , String:511145.b0154 , Swiss-Model:P23893 , UniProt:P23893

Relationship Links: InterPro:IN-FAMILY:IPR004639 , InterPro:IN-FAMILY:IPR005814 , InterPro:IN-FAMILY:IPR015421 , InterPro:IN-FAMILY:IPR015422 , InterPro:IN-FAMILY:IPR015424 , Panther:IN-FAMILY:PTHR11986 , Pfam:IN-FAMILY:PF00202 , Prosite:IN-FAMILY:PS00600

In Paralogous Gene Group: 54 (7 members)

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

Genetic Regulation Schematic: ?

Genetic regulation schematic for hemL

GO Terms:

Biological Process: GO:0006782 - protoporphyrinogen IX biosynthetic process Inferred from experiment Inferred by computational analysis [UniProtGOA12, Nishimura93a]
GO:0033014 - tetrapyrrole biosynthetic process Inferred from experiment Inferred by computational analysis [GOA01a, Ilag92]
GO:0006779 - porphyrin-containing compound biosynthetic process Inferred by computational analysis [UniProtGOA11a, GOA06]
Molecular Function: GO:0005515 - protein binding Inferred from experiment [Rajagopala14, Luer05]
GO:0042286 - glutamate-1-semialdehyde 2,1-aminomutase activity Inferred from experiment Inferred by computational analysis [GOA06, GOA01, GOA01a, Ilag92]
GO:0042802 - identical protein binding Inferred from experiment [Ilag91]
GO:0003824 - catalytic activity Inferred by computational analysis [GOA01a]
GO:0008483 - transaminase activity Inferred by computational analysis [GOA01a]
GO:0016853 - isomerase activity Inferred by computational analysis [UniProtGOA11a]
GO:0030170 - pyridoxal phosphate binding Inferred by computational analysis [GOA01a]
Cellular Component: GO:0005829 - cytosol Inferred from experiment [Lasserre06]
GO:0005737 - cytoplasm Inferred by computational analysis [UniProtGOA11, UniProtGOA11a, GOA06]

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

Essentiality data for hemL knockouts: ?

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

Last-Curated ? 10-Jun-2013 by Kubo A , SRI International

Enzymatic reaction of: glutamate-1-semialdehyde aminotransferase

Synonyms: glutamate-1-semialdehyde 2,1-aminomutase, GSA, GSA-AT, (S)-4-amino-5-oxopentoate 4,5-aminomutase, GSA aminotransferase

EC Number:

(S)-4-amino-5-oxopentanoate <=> 5-aminolevulinate

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 direction shown.

In Pathways: tetrapyrrole biosynthesis I (from glutamate)

Cofactors or Prosthetic Groups: pyridoxal 5'-phosphate [Comment 2, Ilag92]

Inhibitors (Unknown Mechanism): gabaculine [Ilag91] , carboxymethoxylamine [Ilag91]

Sequence Features

Protein sequence of glutamate-1-semialdehyde aminotransferase with features indicated

Feature Class Location Citations Comment
Sequence-Conflict 2
[Grimm91, Fujita94, UniProt10]
UniProt: (in Ref. 1 and 2);
Sequence-Conflict 9
[Grimm91, Fujita94, UniProt10]
UniProt: (in Ref. 1 and 2);
N6-pyridoxal-phosphate-Lys-Modification 265
UniProt: N6-(pyridoxal phosphate)lysine; Non-Experimental Qualifier: probable.
Mutagenesis-Variant 265
[Ilag92, UniProt11]
UniProt: 2% of wild-type activity.

Gene Local Context (not to scale): ?

Gene local context diagram

Transcription Units:

Transcription-unit diagram

Transcription-unit diagram

Transcription-unit diagram


10/20/97 Gene b0154 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG10432; confirmed by SwissProt match.


Al12: Al Mamun AA, Lombardo MJ, Shee C, Lisewski AM, Gonzalez C, Lin D, Nehring RB, Saint-Ruf C, Gibson JL, Frisch RL, Lichtarge O, Hastings PJ, Rosenberg SM (2012). "Identity and function of a large gene network underlying mutagenic repair of DNA breaks." Science 338(6112);1344-8. PMID: 23224554

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

Fujita94: Fujita N, Mori H, Yura T, Ishihama A (1994). "Systematic sequencing of the Escherichia coli genome: analysis of the 2.4-4.1 min (110,917-193,643 bp) region." Nucleic Acids Res 22(9);1637-9. PMID: 8202364

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."

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

Grimm91: Grimm B, Bull A, Breu V (1991). "Structural genes of glutamate 1-semialdehyde aminotransferase for porphyrin synthesis in a cyanobacterium and Escherichia coli." Mol Gen Genet 225(1);1-10. PMID: 1900346

Ilag91: Ilag LL, Jahn D, Eggertsson G, Soll D (1991). "The Escherichia coli hemL gene encodes glutamate 1-semialdehyde aminotransferase." J Bacteriol 1991;173(11);3408-13. PMID: 2045363

Ilag92: Ilag LL, Jahn D (1992). "Activity and spectroscopic properties of the Escherichia coli glutamate 1-semialdehyde aminotransferase and the putative active site mutant K265R." Biochemistry 31(31);7143-51. PMID: 1643048

Lasserre06: Lasserre JP, Beyne E, Pyndiah S, Lapaillerie D, Claverol S, Bonneu M (2006). "A complexomic study of Escherichia coli using two-dimensional blue native/SDS polyacrylamide gel electrophoresis." Electrophoresis 27(16);3306-21. PMID: 16858726

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

Minagawa03: Minagawa S, Ogasawara H, Kato A, Yamamoto K, Eguchi Y, Oshima T, Mori H, Ishihama A, Utsumi R (2003). "Identification and molecular characterization of the Mg2+ stimulon of Escherichia coli." J Bacteriol 185(13);3696-702. PMID: 12813061

Nishimura93a: Nishimura K, Nakayashiki T, Inokuchi H (1993). "Cloning and sequencing of the hemE gene encoding uroporphyrinogen III decarboxylase (UPD) from Escherichia coli K-12." Gene 133(1);109-13. PMID: 8224882

Rajagopala14: Rajagopala SV, Sikorski P, Kumar A, Mosca R, Vlasblom J, Arnold R, Franca-Koh J, Pakala SB, Phanse S, Ceol A, Hauser R, Siszler G, Wuchty S, Emili A, Babu M, Aloy P, Pieper R, Uetz P (2014). "The binary protein-protein interaction landscape of Escherichia coli." Nat Biotechnol 32(3);285-90. PMID: 24561554

UniProt10: 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.

UniProt11a: UniProt Consortium (2011). "UniProt version 2011-11 released on 2011-11-22 00:00:00." Database.

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

UniProtGOA11a: 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."

Other References Related to Gene Regulation

Ogasawara07: Ogasawara H, Ishida Y, Yamada K, Yamamoto K, Ishihama A (2007). "PdhR (pyruvate dehydrogenase complex regulator) controls the respiratory electron transport system in Escherichia coli." J Bacteriol 189(15);5534-41. PMID: 17513468

Park01: Park K, Choi S, Ko M, Park C (2001). "Novel sigmaF-dependent genes of Escherichia coli found using a specified promoter consensus." FEMS Microbiol Lett 2001;202(2);243-50. PMID: 11520622

Yu06b: Yu HH, Di Russo EG, Rounds MA, Tan M (2006). "Mutational analysis of the promoter recognized by Chlamydia and Escherichia coli sigma(28) RNA polymerase." J Bacteriol 188(15);5524-31. PMID: 16855242

Yu06c: Yu HH, Kibler D, Tan M (2006). "In Silico Prediction and Functional Validation of {sigma}28-Regulated Genes in Chlamydia and Escherichia coli." J Bacteriol 188(23);8206-8212. PMID: 16997971

Zhao07b: Zhao K, Liu M, Burgess RR (2007). "Adaptation in bacterial flagellar and motility systems: from regulon members to 'foraging'-like behavior in E. coli." Nucleic Acids Res 35(13);4441-52. PMID: 17576668

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Please cite the following article in publications resulting from the use of EcoCyc: Nucleic Acids Research 41:D605-12 2013
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