4QH7

LC8 - Ana2 (159-168) Complex

Summary for 4QH7

• Entry DOI: 10.2210/pdb4qh7/pdb
• Related: 4QH8
• Descriptor: Dynein light chain 1, cytoplasmic, Anastral spindle 2 (3 entities in total)
• Functional Keywords: lc8 fold dimer, target dimerization, ana2, cellular, motor protein
• Biological source: Drosophila melanogaster (Fruit fly); More
• Cellular location: Cytoplasm, cytoskeleton: Q24117
• Total number of polymer chains: 8
• Total formula weight: 48334.68

Authors

Slevin, L.K.,Romes, E.R.,Slep, K.C. (deposition date: 2014-05-27, release date: 2014-06-11, Last modification date: 2023-09-20)

Primary citation

Slevin, L.K.,Romes, E.M.,Dandulakis, M.G.,Slep, K.C.
The Mechanism of Dynein Light Chain LC8-mediated Oligomerization of the Ana2 Centriole Duplication Factor.
J.Biol.Chem., 289:20727-20739, 2014

PubMed Abstract: Centrioles play a key role in nucleating polarized microtubule networks. In actively dividing cells, centrioles establish the bipolar mitotic spindle and are essential for genomic stability. Drosophila anastral spindle-2 (Ana2) is a conserved centriole duplication factor. Although recent work has demonstrated that an Ana2-dynein light chain (LC8) centriolar complex is critical for proper spindle positioning in neuroblasts, how Ana2 and LC8 interact is yet to be established. Here we examine the Ana2-LC8 interaction and map two LC8-binding sites within the central region of Ana2, Ana2M (residues 156-251). Ana2 LC8-binding site 1 contains a signature TQT motif and robustly binds LC8 (KD of 1.1 μm), whereas site 2 contains a TQC motif and binds LC8 with lower affinity (KD of 13 μm). Both LC8-binding sites flank a predicted ~34-residue α-helix. We present two independent atomic structures of LC8 dimers in complex with Ana2 LC8-binding site 1 and site 2 peptides. The Ana2 peptides form β-strands that extend a central composite LC8 β-sandwich. LC8 recognizes the signature TQT motif in the first LC8 binding site of Ana2, forming extensive van der Waals contacts and hydrogen bonding with the peptide, whereas the Ana2 site 2 TQC motif forms a uniquely extended β-strand, not observed in other dynein light chain-target complexes. Size exclusion chromatography coupled with multiangle static light scattering demonstrates that LC8 dimers bind Ana2M sites and induce Ana2 tetramerization, yielding an Ana2M4-LC88 complex. LC8-mediated Ana2 oligomerization probably enhances Ana2 avidity for centriole-binding factors and may bridge multiple factors as required during spindle positioning and centriole biogenesis.

PubMed: 24920673
DOI: 10.1074/jbc.M114.576041

Experimental method

X-RAY DIFFRACTION (1.829 Å)