Asparagine deamidation reduces DNA-binding affinity of the Drosophila melanogaster Scr homeodomain

FEBS Lett. 2015 Oct 24;589(21):3237-41. doi: 10.1016/j.febslet.2015.09.020. Epub 2015 Oct 3.

Abstract

Spontaneous deamidation of asparagine is a non-enzymatic post-translational modification of proteins. Residue Asn 321 is the main site of deamidation of the Drosophila melanogaster Hox transcription factor Sex Combs Reduced (Scr). Formation of iso-aspartate, the major deamidation product, is detected by HNCACB triple-resonance NMR spectroscopy. The rate of deamidation is quantified by fitting the decay of Asn NH2 side-chain signals in a time-series of (15)N-(1)H HSQC NMR spectra. The deamidated form of Scr binds to specific DNA target sequences with reduced affinity as determined by an electrophoretic mobility shift assay.

Keywords: Asparagine deamidation; DNA binding; Dissociation constant; Hox transcription factor; NMR spectroscopy; Sex Combs Reduced.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Asparagine / metabolism*
  • Binding Sites
  • DNA / metabolism*
  • Drosophila Proteins / chemistry*
  • Drosophila Proteins / metabolism*
  • Drosophila melanogaster / genetics
  • Drosophila melanogaster / metabolism*
  • Isoaspartic Acid / chemistry
  • Magnetic Resonance Spectroscopy
  • Protein Binding
  • Protein Processing, Post-Translational
  • Transcription Factors / chemistry*
  • Transcription Factors / metabolism*

Substances

  • Drosophila Proteins
  • Isoaspartic Acid
  • Scr protein, Drosophila
  • Transcription Factors
  • Asparagine
  • DNA