1.1.1.B20	evolution	Bdh enzymes can be classified into R-acting or S-acting depending on the chirality of the chiral center introduced by the enzyme at the acetoin C2 atom. Whereas the preference for (3R)-acetoin or (3S)-acetoin is imprinted in the geometry of the substrate-binding pocket, R-acting and S-acting Bdh enzymes belong to different protein families and possess different architectures	-, 760761	
1.1.1.B20	evolution	enzyme BDH belongs to the SDR family, of enzymes	741710	
1.1.1.B20	evolution	enzyme BtBDH contains a GroES-like domain at the N terminus and a NAD(P)-binding domain at the C-terminus. Phylogenetic tree analysis reveals that BtBDH is a member ofthe (2R,3R)-2,3-BDH group. BtBDH has the typical (2R,3R)-2,3-butanediol dehydrogenase properties and belongs to the MDR superfamily. According to previous reports, (2R,3R)-2,3-BDH generally belongs to the MDR family, while meso-2,3-BDH is commonly clustered in the SDR (short chain dehydrogenase/reductase) family	-, 760463	
1.1.1.B20	evolution	phylogenetic analysis	702809	
1.1.1.B20	evolution	the enzyme belongs to the NADH-dependent metal-independent short-chain dehydrogenases/reductase (SDR) family of oxidoreductases	-, 760817	
1.1.1.B20	evolution	the enzyme belongs to the short chain dehydrogenase/reductase family	-, 721906	
1.1.1.B20	evolution	the enzyme belongs to the short-chain dehydrogenases/reductases	761081	
1.1.1.B20	evolution	the enzyme belongs to the shortchain dehydrogenase/reductase superfamily	-, 721397	
1.1.1.B20	malfunction	deletion of bdhA gene successfully blocks the reversible transformation between acetoin and 2,3-butanediol and eliminates the effect of dissolved oxygen on the transformation	-, 762259	
1.1.1.B20	malfunction	deletion of budC causes redox imbalance towards NADH	-, 761003	
1.1.1.B20	malfunction	extending the alpha6 helix of SmBdh to mimic the lower activity Enterobacter cloacae enzyme EcBdh results in reduction of SmBdh function to nearly 3% of the total activity. In great contrast, reduction of the corresponding alpha6 helix of the EcBdh to mimic the SmBdh structure results in about 70% increase in its activity	-, 760761	
1.1.1.B20	malfunction	the amount of meso-2,3-BD is highly reduced in a DELTAacoR mutant lacking the regulatory protein AcoR. The loss of locus pa4153, encoding (2R,3R)-2,3-BDH, has no effect on the ability of this strain to grow in (2S,3S)-2,3-BD but completely impairs its ability to utilize (2R,3R)-2,3-BD and meso-2,3-BD. The complementation of the pa4153 mutant strain with its gene successfully restores the growth ability. The DELTApa4153 PAO1 strain can grow in racemic acetoin, indicating that (2R,3R)-2,3-BDH contributes to 2,3-BD utilization by converting 2,3-BD into acetoin	-, 756608	
1.1.1.B20	malfunction	the budC knockout strain produces only the D-2,3-butanediol isomer with high yield and productivity. Deletion of budC gene causes a slight decrease (about 5-10%) in cell growth	-, 742152	
1.1.1.B20	malfunction	the growth of Bacillus licheniformis mutant strain MW3 (DELTAbudCDELTAgdh) is slightly lower than that of Bacillus licheniformis wild-type strain MW3, but the mutant strain can produce acetoin instead of 2,3-butanediol as its major product	-, 761121	
1.1.1.B20	metabolism	2,3-butanediol (2,3-BD) exists in three stereoisomeric forms: (2R,3R)-2,3-BD, meso-2,3-BD and (2S,3S)-2,3-BD. All three stereoisomers are transformed into acetoin by (2R,3R)-2,3-butanediol dehydrogenase (BDH) or (2S,3S)-2,3-BDH. Acetoin is cleaved to form acetyl-CoA and acetaldehyde by acetoin dehydrogenase enzyme system (AoDH ES). Genes encoding (2R,3R)-2,3-BDH, (2S,3S)-2,3-BDH and the E1 and E2 components of AoDH ES are identified as part of a 2,3-BD utilization operon. In addition, the regulatory protein AcoR promotes the expression of this operon using acetaldehyde, a cleavage product of acetoin, as its direct effector. Proposed model for 2,3-BD utilization in Pseudomonas aeruginosa strain PAO1 in downstream catabolic pathways, overview. Genes pa4148, pa4149, pa4150, pa4151, pa4152 and pa4153 comprise an operon responsible for 2,3-BD utilization, mutational analysis. Acetaldehyde is the direct inducer of the 2,3-BD utilization operon	-, 756608	
1.1.1.B20	metabolism	pathways for the synthesis of 2,3-butanediol in bacteria, overview	741710	
1.1.1.B20	metabolism	the proposed pathway from glucose to 2,3-butanediol in Paenibacillus brasilensis involves the enzyme, overview	-, 760411	
1.1.1.B20	additional information	identification of the the active tunnel of meso-2,3-BDH. The two short alpha-helices positioned away from the alpha4-helix possibly expose the hydrophobic ligand-binding cavity, gating the exit of product and cofactor from the activity pocket. AC binds in the active pocket including Ser139, Gln140, Ala141, Leu149, Tyr152, Gly183, Ile184, and Trp190. Residues Phe212 and Asn146 function as the key product-release sites. Three catalytic residues are Ser139, Tyr152, and Lys156. Docking study using the structure of meso-2,3-BDH (PDB ID 1GEG), molecular dynamics simulation	761081	
1.1.1.B20	additional information	Serratia marcescens is a very efficient producer of meso-2,3-butanediol (meso-2,3-BTD)from glucose	-, 760759	
1.1.1.B20	additional information	SmBdh shows a more extensive supporting hydrogen-bond network in comparison to the other well-studied Bdh enzymes, which enables improved substrate positioning and substrate specificity. The substrate-binding pocket is formed by two protein molecules, not a single peptide as found in all other reported Bdh enzymes. The C-terminus of molecule A protrudes into the groove between alpha7 helix and the alpha-turn alphat1 capping substrate-binding pocket of molecule Asymm and vice versa. The SmBdh active site is populated by a Gln247 residue contributed by the diagonally opposite subunit. The enzyme protein also contains a short alpha6 helix, which provides more efficient entry and exit of molecules from the active site, thereby contributing to enhanced substrate turnover. While coordinated active site formation is a unique structural characteristic of this tetrameric complex, the smaller alpha6 helix and extended hydrogen network contribute towards improved activity and substrate promiscuity of the enzyme. Gln247 plays a crucial role in SmBdh catalysis	-, 760761	
1.1.1.B20	additional information	the enzyme possesses two conserved sequences including the coenzyme binding motif (GxxxGxG) and the active-site motif (YxxxK)	-, 721397	
1.1.1.B20	physiological function	2,3-butanediol (2,3-BD) is a primary microbial metabolite that enhances the virulence of Pseudomonas aeruginosa and alters the lung microbiome. 2,3-BD exists in three stereoisomeric forms: (2R,3R)-2,3-BD, meso-2,3-BD and (2S,3S)-2,3-BD	-, 756608	
1.1.1.B20	physiological function	2,3-butanediol dehydrogenase (BDH) catalyzes the interconversion between acetoin and 2,3-butanediol and is a key enzyme for 2,3-butanediol production	-, 742149	
1.1.1.B20	physiological function	acetoin and 2,3-butanediol can be transformed into each other by 2,3-butanediol dehydrogenase (BDH) using NADH/NAD+ as coenzyme. The main 2,3-butanediol production of strain BS168D is meso-2,3-butanediol and the bdhA gene is only responsible for (2R,3R)-2,3-butanediol synthesis. Oxygen supply in the culture of Bacillus subtilis has an important impact on the product yield, productivity and 2,3-butanediol formation in acetoin fermentation. In general, high oxygen supply favours acetoin formation and decrease 2,3-butanediol final yield	-, 762259	
1.1.1.B20	physiological function	acetoin can be converted to 2,3-butanediol by 2,3-butanediol dehydrogenase (budC) with consumption of NADH	-, 761003	
1.1.1.B20	physiological function	budC encodes the major meso-2,3-butanediol dehydrogenase catalyzing the reversible reaction from acetoin to meso-2,3-butanediol in Bacillus licheniformis	-, 742152	
1.1.1.B20	physiological function	D-(-)-acetoin with an optical purity of 25.9% is produced by PT-BDH	-, 761599	
1.1.1.B20	physiological function	D-(-)-acetoin with an optical purity of 57% is produced by BS-BDH	-, 761599	
1.1.1.B20	physiological function	deletion of BDH1 results in an accumulation of acetoin and a diminution of 2,3-butanediol in two Saccharomyces cerevisiae strains under two different growth conditions	710944	
1.1.1.B20	physiological function	L-(+)-acetoin with an optical purity of 92% is produced by BS-BDH	761599	
1.1.1.B20	physiological function	Paenibacillus brasilensis produces 2,3-butanediol (2,3-BDO). And although the gene encoding (S,S)-2,3-butanediol dehydrogenase (EC 1.1.1.76) is found in the genome of Paenibacillus brasilensis strain PB24, only R,R-2,3-butanediol ((R,R)-2,3-butanediol dehydrogenase, EC 1.1.1.4) and meso-2,3-butanediol are detected by gas chromatography under the growth conditions tested. The enzyme is bifunctional as R,R-2,3-butanediol dehydrogenase/meso-2,3-butanediol dehydrogenase/diacetyl reductase	-, 760411	
1.1.1.B20	physiological function	the meso-2,3-butanediol dehydrogenase (meso-2,3-BDH) catalyzes NAD+-dependent conversion of meso-2,3-butanediol to acetoin (AC), a crucial external energy storage molecule in fermentive bacteria. The interconversion between (3R)-AC and meso-2,3-BD or (3S)-AC and (2S,3S)-2,3-BD is catalyzed by meso-2,3-butanediol dehydrogenase (meso-2,3-BDH)	761081