Publication Abstract from PubMed
Repeat proteins are built of modules, each of which constitutes a structural motif. We have investigated whether fragments of a designed consensus armadillo repeat protein (ArmRP) recognize each other. We examined a split ArmRP consisting of an N-capping repeat (denoted Y), three internal repeats (M), and a C-capping repeat (A). We demonstrate that the C-terminal MA fragment adopts a fold similar to the corresponding part of the entire protein. In contrast, the N-terminal YM2 fragment constitutes a molten globule. The two fragments form a 1:1 YM2:MA complex with a nanomolar dissociation constant essentially identical to the crystal structure of the continuous YM3A protein. Molecular dynamics simulations show that the complex is structurally stable over a 1 mus timescale and reveal the importance of hydrophobic contacts across the interface. We propose that the existence of a stable complex recapitulates possible intermediates in the early evolution of these repeat proteins.
Spontaneous self-assembly of engineered armadillo repeat protein fragments into a folded structure.,Watson RP, Christen MT, Ewald C, Bumbak F, Reichen C, Mihajlovic M, Schmidt E, Guntert P, Caflisch A, Pluckthun A, Zerbe O Structure. 2014 Jul 8;22(7):985-95. doi: 10.1016/j.str.2014.05.002. Epub 2014 Jun, 12. PMID:24931467[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
