PDBsum entry 2mqh

DNA binding protein

PDB id: 2mqh

Contents

Protein chain

72 a.a.

PDB id:

2mqh

Name:

DNA binding protein

Title:

Solution structure of the chlamydomonas reinhardtii nab1 cold shock domain, csd1

Structure:

Nucleic acid binding protein. Chain: a. Fragment: cold shock domain. Synonym: putative nucleic acid binding protein. Engineered: yes

Source:

Chlamydomonas reinhardtii. Organism_taxid: 3055. Gene: chlredraft_126810, nab1, nab1 nucleic acid binding protein. Expressed in: escherichia coli. Expression_system_taxid: 469008.

NMR struc:

20 models

Authors:

A.Sawyer,M.Mobli

Key ref:

A.L.Sawyer et al. (2015). Solution structure of the RNA-binding cold-shock domain of the Chlamydomonas reinhardtii NAB1 protein and insights into RNA recognition. Biochem J, 469, 97. PubMed id: 25919092 DOI: 10.1042/BJ20150217

Date:

20-Jun-14 Release date: 06-May-15

Protein chain

Q8GV23  (Q8GV23_CHLRE) -  Putative nucleic acid binding protein from Chlamydomonas reinhardtii

Seq: 247 a.a.

Struc: 72 a.a.*

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

Enzyme reactions

• Enzyme class: E.C.?

DOI no: 10.1042/BJ20150217

Biochem J 469:97 (2015)

PubMed id: 25919092

Solution structure of the RNA-binding cold-shock domain of the Chlamydomonas reinhardtii NAB1 protein and insights into RNA recognition.

A.L.Sawyer, M.J.Landsberg, I.L.Ross, O.Kruse, M.Mobli, B.Hankamer.

ABSTRACT

Light-harvesting complex (LHC) proteins are among the most abundant proteins on Earth and play critical roles in photosynthesis, both in light capture and in photoprotective mechanisms. The Chlamydomonas reinhardtii nucleic acid-binding protein 1 (NAB1) is a negative regulator of LHC protein translation. Its N-terminal cold-shock domain (CSD) binds to a 13-nt element [CSD consensus sequence (CSDCS)] found in the mRNA of specific LHC proteins associated with Photosystem II (PSII), an interaction which regulates LHC expression and, consequently, PSII-associated antenna size, structure and function. In the present study, we elucidated the solution structure of the NAB1 CSD as determined by heteronuclear NMR. The CSD adopts a characteristic five-stranded anti parallel β-barrel fold. Upon addition of CSDCS RNA, a large number of NMR chemical shift perturbations were observed, corresponding primarily to surface-exposed residues within the highly conserved β2- and β3-strands in the canonical RNA-binding region, but also to residues on β-strand 5 extending the positive surface patch and the overall RNA-binding site. Additional chemical shift perturbations that accompanied RNA binding involved buried residues, suggesting that transcript recognition is accompanied by conformational change. Our results indicate that NAB1 associates with RNA transcripts through a mechanism involving its CSD that is conserved with mechanisms of sequence-specific nucleic acid recognition employed by ancestrally related bacterial cold-shock proteins (CSPs).