Structural and biochemical characterization of the Bacillus cereus 3-hydroxyisobutyrate dehydrogenase.
The 3-hydroxyisobutyrate dehydrogenase (HIBADH) family catalyzes the NAD(+)- or NADP(+)-dependent oxidation of various β-hydroxyacid substrates into their cognate semialdehydes for diverse metabolic pathways. Because HIBADH group members exhibit different substrate specificities, the substrate-recognition mode of each enzyme should be individually characterized. In the current study, we report the biochemical and structural analysis of a HIBADH group enzyme from Bacillus cereus (bcHIBADH). bcHIBADH mediates a dehydrogenation reaction on S-3-hydroxyisobutyrate substrate with high catalytic efficiency in an NAD(+)-dependent manner; it also oxidizes l-serine and 3-hydroxypropionate with lower activity. bcHIBADH consists of two domains and is further assembled into a functional dimer rather than a tetramer that has been commonly observed in other prokaryotic HIBADH group members. In the bcHIBADH structure, the interdomain cleft forms a putative active site and simultaneously accommodates both an NAD(+) cofactor and a substrate mimic. Our structure-based comparative analysis highlights structural motifs that are important in the cofactor and substrate recognition of the HIBADH group.
Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon 24341, Republic of Korea.
Sun Cheol
SC
Park
Department of Molecular Bioscience, School of Biomedical Science, Kangwon National University, Chuncheon 24341, Republic of Korea.
Pyeung-Hyeun
PH
Kim
College of Veterinary Medicine, Kangwon National University, Chuncheon 24341, Republic of Korea.
Geun-Shik
GS
Lee
Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon 24341, Republic of Korea.
Seung Goo
SG
Kang
Laboratory of Microbiology and Immunology, College of Pharmacy, Kangwon National University, Chuncheon 24341, Republic of Korea.
Hyun-Jeong
HJ
Ko
Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon 24341, Republic of Korea; Institute of Bioscience and Biotechnology, Kangwon National University, Chuncheon 24341, Republic of Korea. Electronic address: sungil@kangwon.ac.kr.
Sung-Il
SI
Yoon
D000429:Alcohol Oxidoreductases / Q000737:chemistry* / Q000648:ultrastructure*; D000595:Amino Acid Sequence; D001409:Bacillus cereus / Q000201:enzymology*; D001665:Binding Sites; D004789:Enzyme Activation; D008969:Molecular Sequence Data; D011485:Protein Binding; D011487:Protein Conformation; D000072417:Protein Domains; D013379:Substrate Specificity
D000429:Alcohol Oxidoreductases; C021398:3-hydroxyisobutyrate dehydrogenase
3-hydroxyisobutyrate dehydrogenase; Bacillus cereus; Crystal structure; Substrate; β-hydroxyacid dehydrogenase