Anomalies in the refinement of isoleucine.
Acta Crystallogr D Biol Crystallogr
; 70(Pt 4): 1037-49, 2014 Apr.
Article
em En
| MEDLINE
| ID: mdl-24699648
ABSTRACT
A study of isoleucines in protein structures solved using X-ray crystallography revealed a series of systematic trends for the two side-chain torsion angles χ1 and χ2 dependent on the resolution, secondary structure and refinement software used. The average torsion angles for the nine rotamers were similar in high-resolution structures solved using either the REFMAC, CNS or PHENIX software. However, at low resolution these programs often refine towards somewhat different χ1 and χ2 values. Small systematic differences can be observed between refinement software that uses molecular dynamics-type energy terms (for example CNS) and software that does not use these terms (for example REFMAC). Detailing the standard torsion angles used in refinement software can improve the refinement of protein structures. The target values in the molecular dynamics-type energy functions can also be improved.
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Texto completo:
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Isoleucina
Idioma:
En
Ano de publicação:
2014
Tipo de documento:
Article