PDBsum entry 5l3r

Protein transport

PDB id: 5l3r

Contents

Protein chains

267 a.a.

290 a.a.

Ligands

GCP ×4

GOL ×2

Metals

_MG ×4

Waters ×140

PDB id:

5l3r

Name:

Protein transport

Title:

Structure of the gtpase heterodimer of chloroplast srp54 and ftsy from arabidopsis thaliana

Structure:

Signal recognition particle 54 kda protein, chloroplastic. Chain: a, c. Synonym: cpsrp54,ffc. Engineered: yes. Cell division protein ftsy homolog, chloroplastic. Chain: b, d. Synonym: chloroplast srp receptor homolog,alpha subunit cpftsy,fused signal recognition particle receptor. Engineered: yes

Source:

Arabidopsis thaliana. Mouse-ear cress. Organism_taxid: 3702. Gene: ffc, cpsrp54, at5g03940, f8f6_150. Expressed in: escherichia coli. Expression_system_taxid: 562. Gene: cpftsy, ftsy, at2g45770, f4i18.25. Expression_system_taxid: 562

Resolution:

2.50Å R-factor: 0.175 R-free: 0.218

Authors:

G.Bange,J.Kribelbauer,K.Wild,I.Sinning

Key ref:

K.Wild et al. (2016). Structural Basis for Conserved Regulation and Adaptation of the Signal Recognition Particle Targeting Complex. J Mol Biol, 428, 2880-2897. PubMed id: 27241309 DOI: 10.1016/j.jmb.2016.05.015

Date:

24-May-16 Release date: 08-Jun-16

Protein chains

P37107  (SR54C_ARATH) -  Signal recognition particle subunit SRP54, chloroplastic from Arabidopsis thaliana

Seq: 564 a.a.

Struc: 267 a.a.

Protein chains

O80842  (CFTSY_ARATH) -  Cell division protein FtsY homolog, chloroplastic from Arabidopsis thaliana

Seq: 366 a.a.

Struc: 290 a.a.*

* PDB and UniProt seqs differ at 3 residue positions (black crosses)

Enzyme reactions

• Enzyme class 1: Chains A, C: E.C.3.6.5.4 - signal-recognition-particle GTPase.
• Reaction: GTP + H2O = GDP + phosphate + H⁺

GTP + H2O = GDP (Bound ligand (Het Group name = GCP) matches with 81.82% similarity) + phosphate + H(+)

• Enzyme class 2: Chains B, D: E.C.?

Note, where more than one E.C. class is given (as above), each may correspond to a different protein domain or, in the case of polyprotein precursors, to a different mature protein.

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

reference

DOI no: 10.1016/j.jmb.2016.05.015

J Mol Biol 428:2880-2897 (2016)

PubMed id: 27241309

Structural Basis for Conserved Regulation and Adaptation of the Signal Recognition Particle Targeting Complex.

K.Wild, G.Bange, D.Motiejunas, J.Kribelbauer, A.Hendricks, B.Segnitz, R.C.Wade, I.Sinning.

ABSTRACT

The signal recognition particle (SRP) is a ribonucleoprotein complex with a key role in targeting and insertion of membrane proteins. The two SRP GTPases, SRP54 (Ffh in bacteria) and FtsY (SRα in eukaryotes), form the core of the targeting complex (TC) regulating the SRP cycle. The architecture of the TC and its stimulation by RNA has been described for the bacterial SRP system while this information is lacking for other domains of life. Here, we present the crystal structures of the GTPase heterodimers of archaeal (Sulfolobus solfataricus), eukaryotic (Homo sapiens), and chloroplast (Arabidopsis thaliana) SRP systems. The comprehensive structural comparison combined with Brownian dynamics simulations of TC formation allows for the description of the general blueprint and of specific adaptations of the quasi-symmetric heterodimer. Our work defines conserved external nucleotide-binding sites for SRP GTPase activation by RNA. Structural analyses of the GDP-bound, post-hydrolysis states reveal a conserved, magnesium-sensitive switch within the I-box. Overall, we provide a general model for SRP cycle regulation by RNA.