Biochemical characterization of bacterial FeoBs: A perspective on nucleotide specificity

• Published in: Archives of biochemistry and biophysics 2020-05, Vol.685, p.108350-108350, Article 108350
• Main Authors: Shin, Minhye, Park, Jinsub, Jin, Yerin, Kim, In Jung, Payne, Shelley M., Kim, Kyoung Heon
• Format: Article
• Language: English
• Subjects: Adenosine Triphosphatases - chemistry; Adenosine Triphosphatases - metabolism; Adenosine Triphosphate - chemistry; Amino Acid Sequence; ATPase; Bacteria - enzymology; Bacterial Proteins - chemistry; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Cation Transport Proteins - chemistry; Cation Transport Proteins - genetics; Cation Transport Proteins - metabolism; Feo; Ferrous iron transport; GTP Phosphohydrolases - chemistry; GTP Phosphohydrolases - metabolism; GTPase; Guanosine Triphosphate - chemistry; Hydrolysis; Mutagenesis, Site-Directed; Mutation; Nucleoside-Triphosphatase - chemistry; Nucleoside-Triphosphatase - metabolism; Potassium; Potassium - metabolism; Protein Binding; Sequence Alignment; Substrate Specificity
• ISSN: 0003-9861; 1096-0384
• DOI: 10.1016/j.abb.2020.108350

Iron is an essential requirement for the survival and virulence of most bacteria. The bacterial ferrous iron transporter protein FeoB functions as a major reduced iron transporter in prokaryotes, but its biochemical mechanism has not been fully elucidated. In the present study, we compared enzymatic properties of the cytosolic portions of pathogenic bacterial FeoBs to elucidate each bacterial strain-specific characteristic of the Feo system. We show that bacterial FeoBs are classified into two distinct groups that possess either a sole GTPase or an NTPase with a substrate promiscuity. This difference in nucleotide preference alters cellular requirements for monovalent and divalent cations. While the hydrolytic activity of the GTP-dependent FeoBs was stimulated by potassium, the action of the NTP-dependent FeoBs was not significantly affected by the presence of monovalent cations. Mutation of Asn11, having a role in potassium-dependent GTP hydrolysis, changed nucleotide specificity of the NTP-dependent FeoB, resulting in loss of ATPase activity. Sequence analysis suggested a possible association of alanine in the G5 motif for the NTP-dependent activity in FeoBs. This demonstration of the distinct enzymatic properties of bacterial FeoBs provides important insights into mechanistic details of Feo iron transport processes, as well as offers a promising species-specific anti-virulence target.