Structure determination of the O-methyltransferase NovP using the 'free lunch algorithm' as implemented in SHELXE

NovP is an S-adenosyl-l-methionine-dependent O-methyltransferase from Streptomyces spheroides (subunit MW = 29 967 Da). Recombinant N-terminally His-tagged NovP crystallizes in space group P2, with approximate unit-cell parameters a = 51.81, b = 46.04, c = 61.22 Å, β = 105.0°, giving a solvent conte...

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Detalles Bibliográficos
Autores: Usón, Isabel, Stevenson, Clare E. M., Lawson, David M., Sheldrick, George M.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2007
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/113906
Acceso en línea:http://hdl.handle.net/10261/113906
Access Level:acceso abierto
Palabra clave:Antibiotic biosynthesis
Free lunch algorithm
SHELXE
NovP
O-methyltransferase
Chain tracing
Descripción
Sumario:NovP is an S-adenosyl-l-methionine-dependent O-methyltransferase from Streptomyces spheroides (subunit MW = 29 967 Da). Recombinant N-terminally His-tagged NovP crystallizes in space group P2, with approximate unit-cell parameters a = 51.81, b = 46.04, c = 61.22 Å, β = 105.0°, giving a solvent content of 44% for a single copy of the His-tagged protomer per asymmetric unit. Native synchrotron data to a resolution of 1.35 Å were combined with three other native data sets collected at lower resolution (both in-house and at the synchrotron) for the sake of completeness and better scaling. Data to 2.45 Å resolution were subsequently recorded in-house from a single mercury derivative. Three partial mercury sites could be located with SHELXD, but the resulting phases had a mean error of about 81° and in our hands did not yield an interpretable map using standard automated software. Nevertheless, the structure of NovP could be solved by first tracing a small part of the structure by hand and then extrapolating within and beyond the experimental resolution limit using the 'free lunch algorithm' in SHELXE. The resulting phases have a mean phase error of 17° relative to a refined model. © International Union of Crystallography 2007.