S.Fang
et al.
(2013).
Structural insight into plant programmed cell death mediated by BAG proteins in Arabidopsis thaliana.
Acta Crystallogr D Biol Crystallogr,
69,
934-945.
PubMed id: 23695238
DOI: 10.1107/S0907444913003624
Structural insight into plant programmed cell death mediated by BAG proteins in Arabidopsis thaliana.
S.Fang,
L.Li,
B.Cui,
S.Men,
Y.Shen,
X.Yang.
ABSTRACT
The recently identified plant Bcl-2-associated athanogene (BAG) family plays an
extensive role in plant programmed cell death (PCD) processes ranging from
growth and development to stress responses and even cell death. In the
Arabidopsis thaliana BAG (AtBAG) protein family, four members (AtBAG1-4) have a
domain organization similar to that of mammalian BAG proteins. Here, crystal
structures of the BAG domains (BDs) of AtBAG1-4 have been determined; they have
high homology and adopt a structure comprising three short parallel α-helices,
similar to some mammalian BAG proteins. The crystal structure of a complex of
the AtBAG1 ubiquitin-like domain and BAG domain (UBD) with the Hsc70
nucleotide-binding domain (NBD) was also determined. The binding of the AtBAG1
BD to the Hsc70 NBD induces conformational change of the Hsc70 NBD to the open
state and reduces the affinity of the NBD for ADP. In vivo studies showed that
bag2-1 mutant plants are larger than wild-type plants when growing under normal
conditions, indicating that the AtBAG proteins might regulate plant PCD and
confer tolerance to stresses in plants. These structural and functional analyses
indicate that the AtBAG proteins function as nucleotide-exchange factors for
Hsp70/Hsc70 in A. thaliana and that the mechanism of regulation of
chaperone-mediated protein folding is conserved in plants.
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