Protein-protein interactions within the Fatty Acid Synthase-II system of Mycobacterium tuberculosis are essential for mycobacterial viability.
Despite the existence of efficient chemotherapy, tuberculosis remains a leading cause of mortality worldwide. New drugs are urgently needed to reduce the potential impact of the emergence of multidrug-resistant strains of the causative agent Mycobacterium tuberculosis (Mtb). The front-line antibiotic isoniazid (INH), and several other drugs, target the biosynthesis of mycolic acids and especially the Fatty Acid Synthase-II (FAS-II) elongation system. This biosynthetic pathway is essential and specific for mycobacteria and still represents a valuable system for the search of new anti-tuberculous agents. Several data, in the literature, suggest the existence of protein-protein interactions within the FAS-II system. These interactions themselves might serve as targets for a new generation of drugs directed against Mtb. By using an extensive in vivo yeast two-hybrid approach and in vitro co-immunoprecipitation, we have demonstrated the existence of both homotypic and heterotypic interactions between the known components of FAS-II. The condensing enzymes KasA, KasB and mtFabH interact with each other and with the reductases MabA and InhA. Furthermore, we have designed and constructed point mutations of the FAS-II reductase MabA, able to disrupt its homotypic interactions and perturb the interaction pattern of this protein within FAS-II. Finally, we showed by a transdominant genetic approach that these mutants are dominant negative in both non-pathogenic and pathogenic mycobacteria. These data allowed us to draw a dynamic model of the organization of FAS-II. They also represent an important step towards the design of a new generation of anti-tuberculous agents, as being inhibitors of essential protein-protein interactions.
Veyron-Churlet
Romain
R
Département Mécanismes Moléculaires des Infections Mycobactériennes, Institut de Pharmacologie et de Biologie Structurale, Centre National de la Recherche Scientifique, 205 route de Narbonne, 31077 Toulouse Cedex 04, France.
Guerrini
Olivier
O
Mourey
Lionel
L
Daffé
Mamadou
M
Zerbib
Didier
D
D015099:3-Oxoacyl-(Acyl-Carrier-Protein) Synthase / Q000378:metabolism; D000123:Acetyltransferases / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D054889:Fatty Acid Synthase, Type II; D005816:Genetic Complementation Test; D047468:Immunoprecipitation; D008958:Models, Molecular; D009097:Multienzyme Complexes / Q000235:genetics / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D009169:Mycobacterium tuberculosis / Q000201:enzymology* / Q000502:physiology; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism; D017354:Point Mutation; D011485:Protein Binding; D025941:Protein Interaction Mapping; D020798:Two-Hybrid System Techniques
D001426:Bacterial Proteins; D009097:Multienzyme Complexes; D010088:Oxidoreductases; C085257:InhA protein, Mycobacterium; D000123:Acetyltransferases; C444656:KasB protein, Mycobacterium tuberculosis; D015099:3-Oxoacyl-(Acyl-Carrier-Protein) Synthase; D054889:Fatty Acid Synthase, Type II