PDBsum entry 1m1h

Transcription

PDB id: 1m1h

Contents

Protein chain

182 a.a. *

Waters ×296

* Residue conservation analysis

PDB id:

1m1h

Name:

Transcription

Title:

Crystal structure of aquifex aeolicus n-utilization substance g (nusg), space group i222

Structure:

Transcription antitermination protein nusg. Chain: a. Engineered: yes

Source:

Aquifex aeolicus. Organism_taxid: 63363. Expressed in: escherichia coli. Expression_system_taxid: 562

Resolution:

1.95Å R-factor: 0.234 R-free: 0.259

Authors:

T.Steiner,J.T.Kaiser,S.Marinkovic,R.Huber,M.C.Wahl

Key ref:

T.Steiner et al. (2002). Crystal structures of transcription factor NusG in light of its nucleic acid- and protein-binding activities. EMBO J, 21, 4641-4653. PubMed id: 12198166 DOI: 10.1093/emboj/cdf455

Date:

19-Jun-02 Release date: 04-Feb-03

Protein chain

O67757  (NUSG_AQUAE) -  Transcription termination/antitermination protein NusG from Aquifex aeolicus (strain VF5)

Seq: 248 a.a.

Struc: 182 a.a.

DOI no: 10.1093/emboj/cdf455

EMBO J 21:4641-4653 (2002)

PubMed id: 12198166

Crystal structures of transcription factor NusG in light of its nucleic acid- and protein-binding activities.

T.Steiner, J.T.Kaiser, S.Marinkoviç, R.Huber, M.C.Wahl.

ABSTRACT

Microbial transcription modulator NusG interacts with RNA polymerase and termination factor rho, displaying striking functional homology to eukaryotic Spt5. The protein is also a translational regulator. We have determined crystal structures of Aquifex aeolicus NusG showing a modular design: an N-terminal RNP-like domain, a C-terminal element with a KOW sequence motif and a species-specific immunoglobulin-like fold. The structures reveal bona fide nucleic acid binding sites, and nucleic acid binding activities can be detected for NusG from three organisms and for the KOW element alone. A conserved KOW domain is defined as a new class of nucleic acid binding folds. This module is a close structural homolog of tudor protein-protein interaction motifs. Putative protein binding sites for the RNP and KOW domains can be deduced, which differ from the areas implicated in nucleic acid interactions. The results strongly argue that both protein and nucleic acid contacts are important for NusG's functions and that the factor can act as an adaptor mediating indirect protein-nucleic acid associations.

Selected figure(s)

Figure 4.
Figure 4 (A) Superposition of aaeNusG domain III (gold), r-protein L24 (blue) and the SMN tudor domain (red). F211 of aaeNusG and Y109 of the tudor domain, presumably important for contacting other proteins, are shown in ball-and-stick. (B) Domain III in complex with RNA molecules according to the L24−rRNA structure. The sequence originally identified as the KOW element is shown in red.

Figure 6.
Figure 6 (A) Deduced nucleic acid (brown) and protein (green) interaction sites mapped onto the aaeNusG surface. The left panel is in the same orientation as Figure 2C. The three domains are labeled. Numbers identify potential interactions sites. 1, S6-like nucleic acid interaction site; 2, U1A-like nucleic acid interaction site; 3, nucleic acid interaction site mapped by L24−rRNA contacts; 4, S18-like protein interaction site; 5, tudor-like protein interaction site. If helix 3 of the RNP motif was removed upon U1A-like nucleic acid interaction, additional contact sites would become uncovered. Interaction sites that could not be deduced from the structures may also exist in domain II. (B) Stereo-ribbon plot of aaeNusG with the mutated residues in magenta (with phenotype) and light blue (no phenotype).

The above figures are reprinted from an Open Access publication published by Macmillan Publishers Ltd: EMBO J (2002, 21, 4641-4653) copyright 2002.

Figures were selected by an automated process.