Structural basis of diverse sequence-dependent target recognition by the 8 kDa dynein light chain

J Mol Biol. 2001 Feb 9;306(1):97-108. doi: 10.1006/jmbi.2000.4374.

Abstract

Dyneins are multi-subunit molecular motors that translocate molecular cargoes along microtubules. Other than acting as an essential component of the dynein motor complex, the 89-residue subunit of dynein light chain (DLC8) also regulates a number of other biological events by binding to various proteins and enzymes. Currently known DLC8 targets include neuronal nitric oxide synthase; the proapoptotic Bcl-2 family member protein designated Bim; a Drosophila RNA localization protein Swallow, myosin V, neuronal scaffolding protein GKAP, and IkappaBalpha, an inhibitor of the NFkappaB transcription factor. The DLC8-binding domains of the various targets are confined within a short, continuous stretch of amino acid residues. However, these domains do not share any obvious sequence homology with each other. Here, the three-dimensional structures of DLC8 complexed with two peptides corresponding to the DLC8-binding domains of neuronal nitric oxide synthase and Bim, respectively, were determined by NMR spectroscopy. Although the two DLC8-binding peptides have entirely different amino acid sequences, both peptides bind to the protein with a remarkable similar conformation by engaging the symmetric DLC8 dimer through antiparallel beta-sheet augmentation via the beta2 strand of the protein. Structural comparison indicates that the two target peptides use different regions within the conformational flexible peptide-binding channels to achieve binding specificity. We have also re-determined the apo-form solution structure of DLC8 in this work. The structures of the DLC8/target peptide complexes, together with the dynamic properties of the protein, provide a molecular basis of DLC8's diverse amino acid sequence-dependent target recognition.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Apoproteins / chemistry
  • Apoproteins / metabolism
  • Apoptosis Regulatory Proteins
  • Bcl-2-Like Protein 11
  • Binding Sites
  • Carrier Proteins / chemistry*
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Dimerization
  • Drosophila Proteins*
  • Dyneins
  • Membrane Proteins*
  • Models, Molecular
  • Molecular Weight
  • Mutation / genetics
  • Nitric Oxide Synthase / chemistry
  • Nitric Oxide Synthase / genetics
  • Nitric Oxide Synthase / metabolism*
  • Nitric Oxide Synthase Type I
  • Nuclear Magnetic Resonance, Biomolecular
  • Peptide Fragments / chemistry
  • Peptide Fragments / genetics
  • Peptide Fragments / metabolism*
  • Pliability
  • Protein Structure, Secondary
  • Protein Structure, Tertiary
  • Proto-Oncogene Proteins*
  • Rats
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / metabolism
  • Sequence Alignment
  • Substrate Specificity

Substances

  • Apoproteins
  • Apoptosis Regulatory Proteins
  • Bcl-2-Like Protein 11
  • Bcl2l11 protein, rat
  • Carrier Proteins
  • Drosophila Proteins
  • Membrane Proteins
  • Peptide Fragments
  • Proto-Oncogene Proteins
  • Recombinant Fusion Proteins
  • ctp protein, Drosophila
  • Nitric Oxide Synthase
  • Nitric Oxide Synthase Type I
  • Nos1 protein, rat
  • Dyneins

Associated data

  • PDB/1F3C
  • PDB/1F95
  • PDB/1F96