1. Structural insights into BirA from Haemophilus influenzae, a bifunctional protein as a biotin protein ligase and a transcriptional repressor.
- Author
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Jeong KH, Son SB, Ko JH, Lee M, and Lee JY
- Subjects
- Crystallography, X-Ray, Amino Acid Sequence, Adenosine Monophosphate metabolism, Adenosine Monophosphate chemistry, Adenosine Monophosphate analogs & derivatives, Protein Multimerization, Protein Binding, Protein Conformation, Binding Sites, Biotinylation, Acetyl-CoA Carboxylase, Fatty Acid Synthase, Type II, Haemophilus influenzae metabolism, Haemophilus influenzae enzymology, Biotin metabolism, Biotin chemistry, Biotin analogs & derivatives, Repressor Proteins metabolism, Repressor Proteins chemistry, Repressor Proteins genetics, Bacterial Proteins metabolism, Bacterial Proteins chemistry, Bacterial Proteins genetics, Carbon-Nitrogen Ligases metabolism, Carbon-Nitrogen Ligases chemistry, Carbon-Nitrogen Ligases genetics, Models, Molecular
- Abstract
Biotin is an essential coenzyme involved in various metabolic processes across all known organisms, with biotinylation being crucial for the activity of carboxylases. BirA from Haemophilus influenzae is a bifunctional protein that acts as a biotin protein ligase and a transcriptional repressor. This study reveals the crystal structures of Hin BirA in both its apo- and holo-(biotinyl-5'-AMP bound) forms. As a class II BirA, it consists of three domains: N-terminal DNA binding domain, central catalytic domain, and C-terminal SH3-like domain. The structural analysis shows that the biotin-binding loop forms an ordered structure upon biotinyl-5'-AMP binding. This facilitates its interaction with the ligand and promotes protein dimerization. Comparative studies with other BirA homologs from different organisms indicate that the residues responsible for binding biotinyl-5'-AMP are highly conserved. This study also utilized AlphaFold2 to model the potential heterodimeric interaction between Hin BirA and biotin carboxyl carrier protein, thereby providing insights into the structural basis for biotinylation. These findings enhance our understanding of the structural and functional characteristics of Hin BirA, highlighting its potential as a target for novel antibiotics that disrupt the bacterial biotin synthesis pathways., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)
- Published
- 2024
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