Structural Basis of the Selectivity of GenN, an Aminoglycoside N-Methyltransferase Involved in Gentamicin Biosynthesis

Autor(es)

Bury, Priscila dos Santos ^[1] ; Huang, Fanglu ^[2] ; Li, Sicong ^[3] ; Sun, Yuhui ^[3] ; Leadlay, Peter F. ^[2] ; Bertacine Dias, Marcio Vinicius ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Biomed Sci, Dept Microbiol, Sao Paulo - Brazil

^[2] Univ Cambridge, Dept Biochem, Cambridge CB2 1GA - England

^[3] Wuhan Univ, Minist Educ, Sch Pharmaceut Sci, Key Lab Combinatorial Biosynth & Drug Discovery, Wuhan, Hubei - Peoples R China

• Tipo de documento: Artigo Científico
• Fonte: ACS Chemical Biology; v. 12, n. 11, p. 2779-2787, NOV 2017.
• Citações Web of Science: 2

Resumo

Gentamicins are heavily methylated, clinically valuable pseudotrisaccharide antibiotics produced by Micromonospora echinospora. GenN has been characterized as an S-adenosyl-l-methionine-dependent methyltransferase with low sequence similarity to other enzymes. It is responsible for the 3?-N-methylation of 3 `'-dehydro-3 `'-amino-gentamicin A2, an essential modification of ring III in the biosynthetic pathway to the gentamicin C complex. Purified recombinant GenN also efficiently catalyzes 3 `'-N-methylation of related aminoglycosides kanamycin B and tobramycin, which both contain an additional hydroxymethyl group at the C5 `' position in ring III. We have obtained eight cocrystal structures of GenN, at a resolution of 2.2 angstrom or better, including the binary complex of GenN and S-adenosyl-l-homocysteine (SAH) and the ternary complexes of GenN, SAH, and several aminoglycosides. The GenN structure reveals several features not observed in any other N-methyltransferase that fit it for its role in gentamicin biosynthesis. These include a novel N-terminal domain that might be involved in protein:protein interaction with upstream enzymes of the gentamicin X2 biosynthesis and two long loops that are involved in aminoglycoside substrate recognition. In addition, the analysis of structures of GenN in complex with different ligands, supported by the results of active site mutagenesis, has allowed us to propose a catalytic mechanism and has revealed the structural basis for the surprising ability of native GenN to act on these alternative substrates. (AU)

• Processo FAPESP: 14/07843-6 - Análise estrutural de enzimas chaves para biossíntese de gentamicina e sisomicina
• Beneficiário: Priscila dos Santos Bury
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto
• Processo FAPESP: 10/15971-3 - Caracterização estrutural de enzimas envolvidas em vias de biossíntese de antibióticos com interesse biotecnológico
• Beneficiário: Marcio Vinicius Bertacine Dias
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores
• Processo FAPESP: 15/09188-8 - Biossíntese de antibióticos poliéteres e aminoglicosídeos: investigação estrutural de enzimas não usuais ou com aplicabilidade em biologia sintética
• Beneficiário: Marcio Vinicius Bertacine Dias
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 14/50324-0 - Produção de antibióticos aminoglicosídeos menos tóxicos: estrutura, função e estudo de bioengenharia de enzimas biossintéticas chaves
• Beneficiário: Marcio Vinicius Bertacine Dias
• Modalidade de apoio: Auxílio à Pesquisa - Regular