 |
PDBsum entry 4ak9
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Protein transport
|
PDB id
|
|
|
|
4ak9
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
References listed in PDB file
|
|
|
Key reference
|
|
|
Title
|
|
Evolution from the prokaryotic to the higher plant chloroplast signal recognition particle: the signal recognition particle RNA is conserved in plastids of a wide range of photosynthetic organisms.
|
|
|
Authors
|
|
C.Träger,
M.A.Rosenblad,
D.Ziehe,
C.Garcia-Petit,
L.Schrader,
K.Kock,
C.V.Richter,
B.Klinkert,
F.Narberhaus,
C.Herrmann,
E.Hofmann,
H.Aronsson,
D.Schünemann.
|
|
|
Ref.
|
|
Plant Cell, 2012,
24,
4819-4836.
|
|
|
PubMed id
|
|
|
|
|
|
Abstract
|
|
|
The protein targeting signal recognition particle (SRP) pathway in chloroplasts
of higher plants has undergone dramatic evolutionary changes. It disposed of its
RNA, which is an essential SRP component in bacteria, and uses a unique
chloroplast-specific protein cpSRP43. Nevertheless, homologs of the conserved
SRP54 and the SRP receptor, FtsY, are present in higher plant chloroplasts. In
this study, we analyzed the phylogenetic distribution of SRP components in
photosynthetic organisms to elucidate the evolution of the SRP system. We
identified conserved plastid SRP RNAs within all nonspermatophyte land plant
lineages and in all chlorophyte branches. Furthermore, we show the simultaneous
presence of cpSRP43 in these organisms. The function of this novel SRP system
was biochemically and structurally characterized in the moss Physcomitrella
patens. We show that P. patens chloroplast SRP (cpSRP) RNA binds cpSRP54 but has
lost the ability to significantly stimulate the GTPase cycle of SRP54 and FtsY.
Furthermore, the crystal structure at 1.8-Å resolution and the nucleotide
specificity of P. patens cpFtsY was determined and compared with bacterial FtsY
and higher plant chloroplast FtsY. Our data lead to the view that the P. patens
cpSRP system occupies an intermediate position in the evolution from
bacterial-type SRP to higher plant-type cpSRP system.
|
|
|
|
|
|
|
