Download MendeleyBiochemical and Structural Insights into an Fe(II)/ alpha-Ketoglutarate/O2-Dependent Dioxygenase, Kdo 3-Hydroxylase (KdoO).
Joo, S.H., Pemble, C.W., Yang, E.G., Raetz, C.R.H., Chung, H.S.(2018) J Mol Biol 430: 4036-4048
- PubMed: 30092253
- DOI: https://doi.org/10.1016/j.jmb.2018.07.029
- Primary Citation of Related Structures:
5YKA, 5YVZ, 5YW0, 6A2E - PubMed Abstract:
During lipopolysaccharide biosynthesis in several pathogens, including Burkholderia and Yersinia, 3-deoxy-d-manno-oct-2-ulosonic acid (Kdo) 3-hydroxylase, otherwise referred to as KdoO, converts Kdo to d-glycero-d-talo-oct-2-ulosonic acid (Ko) in an Fe(II)/α-ketoglutarate (α-KG)/O 2 -dependent manner. This conversion renders the bacterial outer membrane more stable and resistant to stresses such as an acidic environment. KdoO is a membrane-associated, deoxy-sugar hydroxylase that does not show significant sequence identity with any known enzymes, and its structural information has not been previously reported. Here, we report the biochemical and structural characterization of KdoO, Minf_1012 (Kdo MI ), from Methylacidiphilum infernorum V4. The de novo structure of Kdo MI apoprotein indicates that KdoO MI consists of 13 α helices and 11 β strands, and has the jelly roll fold containing a metal binding motif, HXDX 111 H. Structures of Kdo MI bound to Co(II), Kdo MI bound to α-KG and Fe(III), and Kdo MI bound to succinate and Fe(III), in addition to mutagenesis analysis, indicate that His146, His260, and Asp148 play critical roles in Fe(II) binding, while Arg127, Arg162, Arg174, and Trp176 stabilize α-KG. It was also observed that His225 is adjacent to the active site and plays an important role in the catalysis of KdoO MI without affecting substrate binding, possibly being involved in oxygen activation. The crystal structure of KdoO MI is the first completed structure of a deoxy-sugar hydroxylase, and the data presented here have provided mechanistic insights into deoxy-sugar hydroxylase, KdoO, and lipopolysaccharide biosynthesis.
Organizational Affiliation:
Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA; Department of Pharmacy, Daegu Catholic University, Gyeongbuk 38430, South Korea.
