|Gene:||alaC||Accession Numbers: G7242 (EcoCyc), b2379, ECK2375|
AlaC is one of three major alanine-synthesizing transaminases. AlaA and AlaC together account for 90% of glutamic-pyruvic transaminase (GPT) activity in the cell [Kim10].
A homology model of the enzyme based on the crystal structure of AlaA has been generated [PenaSoler14].
An alaC deletion strain has no growth defect, but an alaA avtA alaC triple mutant has a slow growth phenotype in liquid medium. The defect can be rescued by addition of alanine [Kim10, Yoneyama11]. Fitness and competitive growth experiments were performed under different growth conditions. Particularly under oxygen-limiting conditions, the doubling time of the ΔalaC strain in minimal media is increased compared to growth in rich media; unlike for the alaA and avtA mutants, addition of L-alanine returns the doubling time to that observed in DMEM medium. Under competitive growth conditions, the ΔalaC mutation confers a disadvantage compared to wild type even in rich media [PenaSoler14].
Expression of alaC is activated by the transcriptional regulator SgrR. AlaC may thus play a role in glucose-phosphate stress [Vanderpool07]. However, an alaC deletion mutant does not show altered sensitivity to α-methylglucoside, which induces sugar-phosphate stress [Kim10].
|Map Position: [2,495,079 <- 2,496,317] (53.78 centisomes, 194°)||Length: 1239 bp / 412 aa|
Molecular Weight of Polypeptide: 46.216 kD (from nucleotide sequence)
Molecular Weight of Multimer: 87.0 kD (experimental) [Kim10]
Unification Links: ASAP:ABE-0007850 , DIP:DIP-12010N , EchoBASE:EB3950 , EcoGene:EG14198 , EcoliWiki:b2379 , ModBase:P77434 , OU-Microarray:b2379 , PortEco:yfdZ , Pride:P77434 , Protein Model Portal:P77434 , RefSeq:NP_416880 , RegulonDB:G7242 , SMR:P77434 , String:511145.b2379 , UniProt:P77434
In Paralogous Gene Group: 163 (5 members)
|Biological Process:||GO:0006523 - alanine biosynthetic process
GO:0019272 - L-alanine biosynthetic process from pyruvate [Yoneyama11, Kim10]
GO:0030632 - D-alanine biosynthetic process [Yoneyama11]
GO:0009058 - biosynthetic process [GOA01]
|Molecular Function:||GO:0004021 - L-alanine:2-oxoglutarate aminotransferase activity
GO:0008483 - transaminase activity [UniProtGOA11, Kim10]
GO:0042803 - protein homodimerization activity [Kim10]
GO:0003824 - catalytic activity [GOA01]
GO:0016740 - transferase activity [UniProtGOA11]
GO:0030170 - pyridoxal phosphate binding [GOA01]
|Cellular Component:||GO:0005737 - cytoplasm
GO:0005829 - cytosol [DiazMejia09]
|MultiFun Terms:||metabolism → biosynthesis of building blocks → amino acids → alanine|
|Growth Medium||Growth?||T (°C)||O2||pH||Osm/L||Growth Observations|
|LB enriched||Yes||37||Aerobic||6.95||Yes [Gerdes03, Comment 1]|
|LB Lennox||Yes||37||Aerobic||7||Yes [Baba06, Comment 2]|
|M9 medium with 1% glycerol||Yes||37||Aerobic||7.2||0.35||Yes [Joyce06, Comment 3]|
|MOPS medium with 0.4% glucose||Yes||37||Aerobic||7.2||0.22||Yes [Baba06, Comment 2]|
Enzymatic reaction of: glutamate-pyruvate aminotransferase
EC Number: 18.104.22.168
The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.
This reaction is reversible.
Markus Krummenacker on Tue Oct 14, 1997:
Gene object created from Blattner lab Genbank (v. M52) entry.
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
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
Gerdes03: Gerdes SY, Scholle MD, Campbell JW, Balazsi G, Ravasz E, Daugherty MD, Somera AL, Kyrpides NC, Anderson I, Gelfand MS, Bhattacharya A, Kapatral V, D'Souza M, Baev MV, Grechkin Y, Mseeh F, Fonstein MY, Overbeek R, Barabasi AL, Oltvai ZN, Osterman AL (2003). "Experimental determination and system level analysis of essential genes in Escherichia coli MG1655." J Bacteriol 185(19);5673-84. PMID: 13129938
Joyce06: Joyce AR, Reed JL, White A, Edwards R, Osterman A, Baba T, Mori H, Lesely SA, Palsson BO, Agarwalla S (2006). "Experimental and computational assessment of conditionally essential genes in Escherichia coli." J Bacteriol 188(23);8259-71. PMID: 17012394
PenaSoler14: Pena-Soler E, Fernandez FJ, Lopez-Estepa M, Garces F, Richardson AJ, Quintana JF, Rudd KE, Coll M, Vega MC (2014). "Structural Analysis and Mutant Growth Properties Reveal Distinctive Enzymatic and Cellular Roles for the Three Major L-Alanine Transaminases of Escherichia coli." PLoS One 9(7);e102139. PMID: 25014014
Yoneyama11: Yoneyama H, Hori H, Lim SJ, Murata T, Ando T, Isogai E, Katsumata R (2011). "Isolation of a Mutant Auxotrophic for L-Alanine and Identification of Three Major Aminotransferases That Synthesize L-Alanine in Escherichia coli." Biosci Biotechnol Biochem 75(5);930-8. PMID: 21597182
Huerta03: Huerta AM, Collado-Vides J (2003). "Sigma70 promoters in Escherichia coli: specific transcription in dense regions of overlapping promoter-like signals." J Mol Biol 333(2);261-78. PMID: 14529615
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