Premium
The BTB domains of the potassium channel tetramerization domain proteins prevalently assume pentameric states
Author(s) -
Smaldone Giovanni,
Pirone Luciano,
Pedone Emilia,
Marlovits Thomas,
Vitagliano Luigi,
Ciccarelli Luciano
Publication year - 2016
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1002/1873-3468.12203
Subject(s) - chemistry , potassium channel , biophysics , protein domain , crystallography , biochemistry , biology , gene
Potassium channel tetramerization domain‐containing ( KCTD ) proteins are involved in fundamental physio‐pathological processes. Here, we report an analysis of the oligomeric state of the Bric‐à‐brack, Tram‐track, Broad complex ( BTB ) domains of seven distinct KCTD s belonging to five major clades of the family evolution tree. Despite their functional and sequence variability, present electron microscopy data highlight the occurrence of well‐defined pentameric states for all domains. Our data also show that these states coexist with alternative forms which include open pentamers. Thermal denaturation analyses conducted using KCTD 1 as a model suggest that, in these proteins, different domains cooperate to their overall stability. Finally, negative‐stain electron micrographs of KCTD 6 BTB in complex with Cullin3 show the presence of assemblies with a five‐pointed pinwheel shape.