Download MendeleyMolecular insights into titin's A-band.
Fleming, J.R., Muller, I., Zacharchenko, T., Diederichs, K., Mayans, O.(2023) J Muscle Res Cell Motil 44: 255-270
- PubMed: 37258982
- DOI: https://doi.org/10.1007/s10974-023-09649-1
- Primary Citation of Related Structures:
8BNQ - PubMed Abstract:
The thick filament-associated A-band region of titin is a highly repetitive component of the titin chain with important scaffolding properties that support thick filament assembly. It also has a demonstrated link to human disease. Despite its functional significance, it remains a largely uncharacterized part of the titin protein. Here, we have performed an analysis of sequence and structure conservation of A-band titin, with emphasis on poly-FnIII tandem components. Specifically, we have applied multi-dimensional sequence pairwise similarity analysis to FnIII domains and complemented this with the crystallographic elucidation of the 3D-structure of the FnIII-triplet A84-A86 from the fourth long super-repeat in the C-zone (C4). Structural models serve here as templates to map sequence conservation onto super-repeat C4, which we show is a prototypical representative of titin's C-zone. This templating identifies positionally conserved residue clusters in C super-repeats with the potential of mediating interactions to thick-filament components. Conservation localizes to two super-repeat positions: Ig domains in position 1 and FnIII domains in position 7. The analysis also allows conclusions to be drawn on the conserved architecture of titin's A-band, as well as revisiting and expanding the evolutionary model of titin's A-band.
Organizational Affiliation:
Department of Biology, University of Konstanz, 78457, Konstanz, Germany.
