|Gene:||rhaD||Accession Numbers: EG11866 (EcoCyc), b3902, ECK3895|
Subunit composition of
rhamnulose-1-phosphate aldolase = [RhaD]4
rhamnulose-1-phosphate aldolase monomer = RhaD
Rhamnulose-1-phosphate aldolase is a class II aldolase that catalyzes the third step in the L-rhamnose degradation pathway.
The enzyme contains 2 molecules of zinc per enzyme complex [Schwartz72a]. If cobalt or selected other divalent metal ions are artificially substituted for zinc, the enzyme has an oxygenase activity in the presence of dihydroxyacetone phosphate [Hixon96].
The enzyme has been crystallized [Chiu69, Schwartz74a], and crystal structures have been solved [Kroemer02, Kroemer03]. A catalytic mechanism was proposed based on results from site-directed mutagenesis in combination with structural information [Kroemer03]. Anisotropic mobility of the N-terminal "antenna domain" supports catalysis [Grueninger08]. Stereospecificity of RhaD has been investigated [Schoevaart00].
RhaD (there called Rua) was used in a study of designed protein-protein associations; certain mutations generated a new contact surface and allowed formation of an octamer [Grueninger08a].
Expression of RhaD is induced by L-rhamnose as well as L-lyxose [Badia91].
rhaD mutants can not utilize rhamnose as a source of carbon [Power67].
|Map Position: [4,091,471 <- 4,092,295] (88.18 centisomes, 317°)||Length: 825 bp / 274 aa|
Molecular Weight of Polypeptide: 30.145 kD (from nucleotide sequence), 32.0 kD (experimental) [Badia89]
Molecular Weight of Multimer: 135.0 kD (experimental) [Chiu69]
Unification Links: ASAP:ABE-0012731, CGSC:289, EchoBASE:EB1812, EcoGene:EG11866, EcoliWiki:B3902, ModBase:P32169, OU-Microarray:b3902, PortEco:rhaD, PR:PRO_000023735, Protein Model Portal:P32169, RefSeq:NP_418338, RegulonDB:EG11866, SMR:P32169, String:511145.b3902, UniProt:P32169
Relationship Links: InterPro:IN-FAMILY:IPR001303, InterPro:IN-FAMILY:IPR013447, PDB:Structure:1GT7, PDB:Structure:1OJR, PDB:Structure:2UYU, PDB:Structure:2UYV, PDB:Structure:2V9O, PDB:Structure:2V29, PDB:Structure:2V2A, PDB:Structure:2V2B, PDB:Structure:2V9E, PDB:Structure:2V9F, PDB:Structure:2V9G, PDB:Structure:2V9I, PDB:Structure:2V9L, PDB:Structure:2V9M, PDB:Structure:2V9N, Pfam:IN-FAMILY:PF00596, Smart:IN-FAMILY:SM01007
|MultiFun Terms:||metabolism → carbon utilization → carbon compounds|
Enzymatic reaction of: rhamnulose-1-phosphate aldolase
Synonyms: L-rhamnulose-1-phosphate lactaldehyde-lyase, RhuA
EC Number: 22.214.171.124L-rhamnulose 1-phosphate ⇄ (S)-lactaldehyde + glycerone phosphate
The direction shown, i.e. which substrates are on the left and right sides, is in accordance with the direction of enzyme catalysis.
This reaction is reversible. [Chiu69]Alternative Substrates for L-rhamnulose 1-phosphate [Chiu75]: L-xylulose 1-phosphate, keto-D-sorbose 1-phosphate
At equilibrium, the reaction mixture contains approximately 75% L-rhamnulose-1-phosphate [Chiu69].
The Km for L-xylulose-1-phosphate is 200 µM and that for D-sorbose-1-phosphate is 1.8 mM [Chiu69].L-rhamnitol 1-phosphate [Chiu75], o-phenanthroline [Chiu75], Li+ [Chiu69, Comment 2] Inhibitors (Unknown Mechanism): Hg2+ [Chiu75], 8-hydroxyquinoline-5-sulfonic acid [Chiu75, Schwartz72a], p-mercuribenzoate [Chiu75, Schwartz72], 2,2'-dipyridyl [Chiu75], EDTA [Schwartz72a, Comment 3]Kinetic Parameters:
|Substrate||Km (μM)||kcat (sec-1)||kcat/Km (sec-1 μM-1)||Citations|
|L-rhamnulose 1-phosphate||10000.0||[Sawada64, BRENDA14]|
|L-rhamnulose 1-phosphate||300.0||38.3||0.13||[Chiu69, BRENDA14]|
|glycerone phosphate||9.1||[Jimenez09, BRENDA14]|
|Pfam PF00596||12 -> 238|
10/20/97 Gene b3902 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG11866; confirmed by SwissProt match.
Badia91: Badia J, Gimenez R, Baldoma L, Barnes E, Fessner WD, Aguilar J (1991). "L-lyxose metabolism employs the L-rhamnose pathway in mutant cells of Escherichia coli adapted to grow on L-lyxose." J Bacteriol 1991;173(16);5144-50. PMID: 1650346
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
Finn14: Finn RD, Bateman A, Clements J, Coggill P, Eberhardt RY, Eddy SR, Heger A, Hetherington K, Holm L, Mistry J, Sonnhammer EL, Tate J, Punta M (2014). "Pfam: the protein families database." Nucleic Acids Res 42(Database issue);D222-30. PMID: 24288371
GarciaJunceda95: Garcia-Junceda E, Shen GJ, Sugai T, Wong CH (1995). "A new strategy for the cloning, overexpression and one step purification of three DHAP-dependent aldolases: rhamnulose-1-phosphate aldolase, fuculose-1-phosphate aldolase and tagatose-1,6-diphosphate aldolase." Bioorg Med Chem 3(7);945-53. PMID: 7582972
Kroemer02: Kroemer M, Schulz GE (2002). "The structure of L-rhamnulose-1-phosphate aldolase (class II) solved by low-resolution SIR phasing and 20-fold NCS averaging." Acta Crystallogr D Biol Crystallogr 58(Pt 5);824-32. PMID: 11976494
Moralejo93: Moralejo P, Egan SM, Hidalgo E, Aguilar J (1993). "Sequencing and characterization of a gene cluster encoding the enzymes for L-rhamnose metabolism in Escherichia coli." J Bacteriol 175(17);5585-94. PMID: 8396120
Holcroft00: Holcroft CC, Egan SM (2000). "Roles of cyclic AMP receptor protein and the carboxyl-terminal domain of the alpha subunit in transcription activation of the Escherichia coli rhaBAD operon." J Bacteriol 182(12);3529-35. PMID: 10852886
Holcroft00a: Holcroft CC, Egan SM (2000). "Interdependence of activation at rhaSR by cyclic AMP receptor protein, the RNA polymerase alpha subunit C-terminal domain, and rhaR." J Bacteriol 2000;182(23);6774-82. PMID: 11073923
Wickstrum05: Wickstrum JR, Santangelo TJ, Egan SM (2005). "Cyclic AMP receptor protein and RhaR synergistically activate transcription from the L-rhamnose-responsive rhaSR promoter in Escherichia coli." J Bacteriol 187(19);6708-18. PMID: 16166533
Wickstrum07: Wickstrum JR, Skredenske JM, Kolin A, Jin DJ, Fang J, Egan SM (2007). "Transcription activation by the DNA-binding domain of the AraC family protein RhaS in the absence of its effector-binding domain." J Bacteriol 189(14);4984-93. PMID: 17513476
Zhao10b: Zhao K, Liu M, Burgess RR (2010). "Promoter and regulon analysis of nitrogen assimilation factor, sigma54, reveal alternative strategy for E. coli MG1655 flagellar biosynthesis." Nucleic Acids Res 38(4);1273-83. PMID: 19969540
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