PDBsum entry 1qm9

Ribonucleoprotein

PDB id: 1qm9

Contents

Protein chain

198 a.a. *

* Residue conservation analysis

PDB id:

1qm9

Name:

Ribonucleoprotein

Title:

Nmr, representative structure

Structure:

Polypyrimidine tract-binding protein. Chain: a. Fragment: RNA binding fragment. Synonym: ptb, ptb-c198, heterogeneous nuclear ribonucleoprotein i, hnrnp i, 57 kd RNA-binding protein pptb-1. Engineered: yes

Source:

Homo sapiens. Human. Organism_taxid: 9606. Cellular_location: nucleus/cytoplasm. Expressed in: escherichia coli. Expression_system_taxid: 469008.

NMR struc:

1 models

Authors:

M.R.Conte,T.Grune,S.Curry,S.Matthews

Key ref:

M.R.Conte et al. (2000). Structure of tandem RNA recognition motifs from polypyrimidine tract binding protein reveals novel features of the RRM fold. EMBO J, 19, 3132-3141. PubMed id: 10856256 DOI: 10.1093/emboj/19.12.3132

Date:

22-Sep-99 Release date: 03-Jul-00

Protein chain

P26599  (PTBP1_HUMAN) -  Polypyrimidine tract-binding protein 1 from Homo sapiens

Seq: 557 a.a.

Struc: 198 a.a.*

* PDB and UniProt seqs differ at 1 residue position (black cross)

DOI no: 10.1093/emboj/19.12.3132

EMBO J 19:3132-3141 (2000)

PubMed id: 10856256

Structure of tandem RNA recognition motifs from polypyrimidine tract binding protein reveals novel features of the RRM fold.

M.R.Conte, T.Grüne, J.Ghuman, G.Kelly, A.Ladas, S.Matthews, S.Curry.

ABSTRACT

Polypyrimidine tract binding protein (PTB), an RNA binding protein containing four RNA recognition motifs (RRMs), is involved in both pre-mRNA splicing and translation initiation directed by picornaviral internal ribosome entry sites. Sequence comparisons previously indicated that PTB is a non-canonical RRM protein. The solution structure of a PTB fragment containing RRMs 3 and 4 shows that the protein consists of two domains connected by a long, flexible linker. The two domains tumble independently in solution, having no fixed relative orientation. In addition to the betaalphabetabetaalphabeta topology, which is characteristic of RRM domains, the C-terminal extension of PTB RRM-3 incorporates an unanticipated fifth beta-strand, which extends the RNA binding surface. The long, disordered polypeptide connecting beta4 and beta5 in RRM-3 is poised above the RNA binding surface and is likely to contribute to RNA recognition. Mutational analyses show that both RRM-3 and RRM-4 contribute to RNA binding specificity and that, despite its unusual sequence, PTB binds RNA in a manner akin to that of other RRM proteins.

Selected figure(s)

Figure 3.
Figure 3 Ribbon diagrams for PTB-34 and Sex-lethal. (A) Comparison of tandem domain structures of PTB and Sex-lethal. The relative orientation of the two domains shown for PTB is arbitrary, as is the structure of the inter-domain linker. The structure of Sex-lethal was solved crystallographically in the presence of bound RNA (Handa et al., 1999), which has been omitted from the figure. (B) Comparison of RRM-3 and RRM-4 domains from PTB with RRM-1 of Sex-lethal. PTB RRM-3 contains an additional strand ( 5) on one side of the RNA binding surface. Note that the conformation shown for the 4– 5 loop is only one of many conformations that are consistent with the data (see Figure 2).

Figure 5.
Figure 5 Overview of protein and RNA constructs used in this study. (A) Schematic depiction of PTB constructs; RRM domains are indicated by shading. (B) Schematic diagram of the EMCV IRES; domain 1 is boxed.

The above figures are reprinted from an Open Access publication published by Macmillan Publishers Ltd: EMBO J (2000, 19, 3132-3141) copyright 2000.

Figures were selected by an automated process.