|Gene:||alaA||Accession Numbers: G7184 (EcoCyc), b2290, ECK2284|
AlaA 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 crystal structure of AlaA has been solved at 2.11 Å resolution. The structure shows a symmetric α2 homodimer typical of fold type I aminotransferases [PenaSoler14].
An alaA deletion strain has no growth defect, but an alaA avtA double mutant forms small colonies on agar plates. An alaA avtA alaC triple mutant has a slow growth phenotype in liquid medium. The defects of the double and triple mutants 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 ΔalaA strain in minimal media is increased compared to growth in rich media. Under competitive growth conditions, the ΔalaA mutation confers a disadvantage compared to wild type even in rich media [PenaSoler14]. alaA was identified in a screen for genes that reduce the lethal effects of stress. An alaA insertion mutant is more sensitive than wild type to mitomycin C and other stresses and less sensitive to 10% SDS [Han10].
The alaA gene was first identified as a mutant with a leaky requirement for alanine or valine [Wang87].
alaA and yfbR may form an operon [Kim10].
|Map Position: [2,405,583 -> 2,406,800] (51.85 centisomes)||Length: 1218 bp / 405 aa|
Molecular Weight of Polypeptide: 45.517 kD (from nucleotide sequence)
Molecular Weight of Multimer: 87.0 kD (experimental) [Kim10]
Unification Links: ASAP:ABE-0007560 , EchoBASE:EB3854 , EcoGene:EG14101 , EcoliWiki:b2290 , ModBase:P0A959 , OU-Microarray:b2290 , PortEco:yfbQ , Pride:P0A959 , Protein Model Portal:P0A959 , RefSeq:NP_416793 , RegulonDB:G7184 , SMR:P0A959 , String:511145.b2290 , Swiss-Model:P0A959 , UniProt:P0A959
Relationship Links: InterPro:IN-FAMILY:IPR004839 , InterPro:IN-FAMILY:IPR015421 , InterPro:IN-FAMILY:IPR015422 , InterPro:IN-FAMILY:IPR015424 , PDB:Structure:4CVQ , Pfam:IN-FAMILY:PF00155 , Prosite:IN-FAMILY:PS00105
In Paralogous Gene Group: 163 (5 members)
|Biological Process:||GO:0006523 - alanine biosynthetic process
GO:0006974 - cellular response to DNA damage stimulus [Han10]
GO:0019272 - L-alanine biosynthetic process from pyruvate [Yoneyama11, Kim10]
GO:0030632 - D-alanine biosynthetic process [Kim10]
GO:0046677 - response to antibiotic [Han10]
GO:0009058 - biosynthetic process [GOA01a]
|Molecular Function:||GO:0004021 - L-alanine:2-oxoglutarate aminotransferase activity
GO:0008483 - transaminase activity [UniProtGOA11a, Kim10]
GO:0030170 - pyridoxal phosphate binding [GOA01a, PenaSoler14]
GO:0042803 - protein homodimerization activity [Kim10]
GO:0003824 - catalytic activity [GOA01a]
GO:0016740 - transferase activity [UniProtGOA11a]
|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 Lennox||Yes||37||Aerobic||7||Yes [Baba06, Comment 1]|
|M9 medium with 1% glycerol||Yes||37||Aerobic||7.2||0.35||Yes [Joyce06, Comment 2]|
|MOPS medium with 0.4% glucose||Yes||37||Aerobic||7.2||0.22||Yes [Baba06, Comment 1]|
Enzymatic reaction of: glutamate-pyruvate aminotransferase
EC Number: 220.127.116.11
The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction of enzyme catalysis.
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
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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