| First Author | Boettcher AJ | Year | 2011 |
| Journal | Structure | Volume | 19 |
| Issue | 2 | Pages | 265-76 |
| PubMed ID | 21300294 | Mgi Jnum | J:245389 |
| Mgi Id | MGI:5919496 | Doi | 10.1016/j.str.2010.12.005 |
| Citation | Boettcher AJ, et al. (2011) Realizing the allosteric potential of the tetrameric protein kinase A RIalpha holoenzyme. Structure 19(2):265-76 |
| abstractText | PKA holoenzymes containing two catalytic (C) subunits and a regulatory (R) subunit dimer are activated cooperatively by cAMP. While cooperativity involves the two tandem cAMP binding domains in each R-subunit, additional cooperativity is associated with the tetramer. Of critical importance is the flexible linker in R that contains an inhibitor site (IS). While the IS becomes ordered in the R:C heterodimer, the overall conformation of the tetramer is mediated largely by the N-Linker that connects the D/D domain to the IS. To understand how the N-Linker contributes to assembly of tetrameric holoenzymes, we engineered a monomeric RIalpha that contains most of the N-Linker, RIalpha(73-244), and crystallized a holoenzyme complex. Part of the N-linker is now ordered by interactions with a symmetry-related dimer. This complex of two symmetry-related dimers forms a tetramer that reveals novel mechanisms for allosteric regulation and has many features associated with full-length holoenzyme. A model of the tetrameric holoenzyme, based on this structure, is consistent with previous small angle X-ray and neutron scattering data, and is validated with new SAXS data and with an RIalpha mutation localized to a novel interface unique to the tetramer. |
