PMID- 18035371
OWN - NLM
STAT- MEDLINE
DCOM- 20071221
LR  - 20240109
IS  - 1089-8638 (Electronic)
IS  - 0022-2836 (Linking)
VI  - 375
IP  - 2
DP  - 2008 Jan 11
TI  - Structure of the chloroplast signal recognition particle (SRP) receptor: domain 
      arrangement modulates SRP-receptor interaction.
PG  - 425-36
AB  - The signal recognition particle (SRP) pathway mediates co-translational targeting 
      of nascent proteins to membranes. Chloroplast SRP is unique in that it does not 
      contain the otherwise universally conserved SRP RNA, which accelerates the 
      association between the SRP guanosine-5'-triphosphate (GTP) binding protein and 
      its receptor FtsY in classical SRP pathways. Recently, we showed that the SRP and 
      SRP receptor (SR) GTPases from chloroplast (cpSRP54 and cpFtsY, respectively) can 
      interact with one another 400-fold more efficiently than their bacterial 
      homologues, thus providing an explanation as to why this novel chloroplast SRP 
      pathway bypasses the requirement for the SRP RNA. Here we report the crystal 
      structure of cpFtsY from Arabidopsis thaliana at 2.0 A resolution. In this 
      chloroplast SR, the N-terminal "N" domain is more tightly packed, and a more 
      extensive interaction surface is formed between the GTPase "G" domain and the N 
      domain than was previously observed in many of its bacterial homologues. As a 
      result, the overall conformation of apo-cpFtsY is closer to that found in the 
      bacterial SRP*FtsY complex than in free bacterial FtsY, especially with regard to 
      the relative orientation of the N and G domains. In contrast, active-site 
      residues in the G domain are mispositioned, explaining the low basal GTP binding 
      and hydrolysis activity of free cpFtsY. This structure emphasizes proper N-G 
      domain arrangement as a key factor in modulating the efficiency of SRP-receptor 
      interaction and helps account, in part, for the faster kinetics at which the 
      chloroplast SR interacts with its binding partner in the absence of an SRP RNA.
FAU - Chandrasekar, Sowmya
AU  - Chandrasekar S
AD  - Division of Chemistry and Chemical Engineering, California Institute of 
      Technology, 1200 E. California Boulevard, Pasadena, CA 91125, USA.
FAU - Chartron, Justin
AU  - Chartron J
FAU - Jaru-Ampornpan, Peera
AU  - Jaru-Ampornpan P
FAU - Shan, Shu-ou
AU  - Shan SO
LA  - eng
SI  - PDB/2OG2
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, Non-P.H.S.
DEP - 20071126
PL  - Netherlands
TA  - J Mol Biol
JT  - Journal of molecular biology
JID - 2985088R
RN  - 0 (Malonates)
RN  - 0 (Receptors, Cytoplasmic and Nuclear)
RN  - 0 (Receptors, Peptide)
RN  - 0 (signal peptide receptor)
RN  - 9KX7ZMG0MK (malonic acid)
RN  - EC 3.6.1.- (GTP Phosphohydrolases)
SB  - IM
MH  - Amino Acid Motifs
MH  - Amino Acid Sequence
MH  - Arabidopsis/chemistry/metabolism
MH  - Binding Sites
MH  - Chloroplasts/*chemistry
MH  - Conserved Sequence
MH  - Crystallography, X-Ray
MH  - GTP Phosphohydrolases/chemistry
MH  - Hydrogen Bonding
MH  - Hydrolysis
MH  - Kinetics
MH  - Malonates/metabolism
MH  - Models, Molecular
MH  - Molecular Sequence Data
MH  - Mutation
MH  - Protein Conformation
MH  - Protein Structure, Secondary
MH  - Protein Structure, Tertiary
MH  - Receptors, Cytoplasmic and Nuclear/*chemistry/genetics/isolation & 
      purification/*metabolism
MH  - Receptors, Peptide/*chemistry/genetics/isolation & purification/*metabolism
MH  - Sequence Homology, Amino Acid
EDAT- 2007/11/24 09:00
MHDA- 2007/12/22 09:00
CRDT- 2007/11/24 09:00
PHST- 2007/05/24 00:00 [received]
PHST- 2007/08/24 00:00 [revised]
PHST- 2007/09/20 00:00 [accepted]
PHST- 2007/11/24 09:00 [pubmed]
PHST- 2007/12/22 09:00 [medline]
PHST- 2007/11/24 09:00 [entrez]
AID - S0022-2836(07)01261-2 [pii]
AID - 10.1016/j.jmb.2007.09.061 [doi]
PST - ppublish
SO  - J Mol Biol. 2008 Jan 11;375(2):425-36. doi: 10.1016/j.jmb.2007.09.061. Epub 2007 
      Nov 26.