INVESTIGADORES
MORENO Silvia Margarita
congresos y reuniones científicas
Título:
Low resolution sotructure of the dimerization domain of Bcy1, the regulatory subunit of yeast PKA
Autor/es:
GONZALEZ BARDECI NICOLAS; CARAMELO JULIO; BLUMENTHAL DONALD; FERNANDEZ NUÑEZ, LUCAS; TURJANSKI ADRIAN; ROSSI SILVIA; MORENO SILVIA
Lugar:
Mendoza
Reunión:
Congreso; XLVIII Reunion Anual de la SAIB; 2012
Institución organizadora:
Sociedad Argentina de Investigacion en bioquimica y Biologia mOlecular
Resumen:
The regulatory (R) subunit of protein kinase A (PKA) from
mammals is dimeric in solution. TheNtermini from both protomers
constitute the docking and dimerization (DD) domain, responsible
for the quaternary structure and for the subcellular localization of
the molecule. This domain consists of an X type four helix bundle
fold. No structural study of this domain from other organisms is
available. Here we present the first structural characterization of the
N terminus of Bcy1, the R subunit of PKA from Saccharomyces
cerevisiae. Using multiple sequence alignments, secondary
structure prediction, and chemical crosslinking, we have shown that
Bcy1 is dimeric in solution and have mapped the region of the
molecule responsible for dimerization. The first 50 aminoacids of
Bcy1 were cloned and overexpressed in . This purified
fragment was shown to be dimeric both by chemical crosslinking
and gel filtration, providing evidence that this is the dimerization
domain of Bcy1. Circular dichroism shows that it is highly helical,
thus resembling DD from mammals. Its melting temperature,
followed by ellipticity at 221 nm, is concentration dependent,
supporting its oligomeric nature. Denaturation is highly reversible,
suggesting a great stability. SAXS experiments were also
performed on this domain. These results suggest that the structure of
this domain is well conserved through evolution.