PDBsum entry: 2jnq

Unknown function

PDB id: 2jnq

Contents

Protein chain

186 a.a. *

* Residue conservation analysis

PDB id:

2jnq

Name:

Unknown function

Title:

Solution structure of a klba intein precursor from methanococcus jannaschii

Structure:

Hypothetical protein mj0781. Chain: a. Fragment: mja klba intein, residues 1-180. Engineered: yes. Mutation: yes

Source:

Methanocaldococcus jannaschii. Organism_taxid: 2190. Expressed in: escherichia coli. Expression_system_taxid: 562.

NMR struc:

1 models

Authors:

M.A.Johnson,M.W.Southworth,T.Herrmann,L.Brace,F.B.Perler, K.A.Wuthrich

Key ref:

m.a.johnson et al. (2007). NMR structure of a KlbA intein precursor from Methanococcus jannaschii Protein Sci, 16, 1316-1328. PubMed id: 17586768 DOI: 10.1110/ps.072816707

Date:

31-Jan-07 Release date: 10-Jul-07

Protein chain

Q58191  (Y781_METJA) -  Uncharacterized protein MJ0781

Seq: 721 a.a.

Struc: 186 a.a.*

* PDB and UniProt seqs differ at 7 residue positions (black crosses)

 Gene Ontology (GO) functional annotation 

• Biological process: intein-mediated protein splicing (1 term)

DOI no: 10.1110/ps.072816707

Protein Sci 16:1316-1328 (2007)

PubMed id: 17586768

NMR structure of a KlbA intein precursor from Methanococcus jannaschii

m.a.johnson, m.w.southworth, t.herrmann, l.brace, f.b.perler, k.wuthrich.

ABSTRACT

Certain proteins of unicellular organisms are translated as precursor polypeptides containing inteins (intervening proteins), which are domains capable of performing protein splicing. These domains, in conjunction with a single residue following the intein, catalyze their own excision from the surrounding protein (extein) in a multistep reaction involving the cleavage of two intein–extein peptide bonds and the formation of a new peptide bond that ligates the two exteins to yield the mature protein. We report here the solution NMR structure of a 186-residue precursor of the KlbA intein from Methanococcus jannaschii, comprising the intein together with N- and C-extein segments of 7 and 11 residues, respectively. The intein is shown to adopt a single, well-defined globular domain, representing a HINT (Hedgehog/Intein)-type topology. Fourteen -strands are arranged in a complex fold that includes four -hairpins and an antiparallel -ribbon, and there is one -helix, which is packed against the -ribbon, and one turn of 3₁₀-helix in the loop between the -strands 8 and 9. The two extein segments show increased disorder, and form only minimal nonbonding contacts with the intein domain. Structure-based mutation experiments resulted in a proposal for functional roles of individual residues in the intein catalytic mechanism.

Selected figure(s)

Figure 1.
Figure 1. (A) Ensemble of 20 CYANA conformers representing the Mja KlbA intein precursor solution structure, superimposed for minimal RMSD of the backbone N, C^alpha, and C^' atom positions of residues 1 to +1. Residue numbers and the N and C termini of the protein are indicated. Helices are colored red, beta-strands blue, and regions without regular secondary structure black. (B) Ribbon presentation of the Mja KlbA intein, with the same orientation as in A. Helices are colored red and beta-strands cyan. Regions of regular secondary structure are labeled, and the N and C termini are indicated. The conformer with minimal RMSD to the mean coordinates of the ensemble in A is shown. (C) Amino acid sequence of the Mja KlbA intein precursor described in this study, and structure-based sequence alignment with the other inteins for which a three-dimensional structure is available. The residue numbers and regular secondary structure elements of the Mja KlbA intein precursor are indicated above the sequence. The residue numbering begins with 1 for the first residue of the intein and ends with 168 at the last residue of the intein. The seven extein residues at the N terminus (7 to 1) and the 11 extein residues at the C terminus (+1 to +11) are underlined, and are numbered separately (italicized numbers). The splice junction residues, and other residues of interest that are discussed in the text, are colored red. All sequences include the amino acid replacements used to generate a construct for structure determination. In the multiple sequence alignment, hyphens (-) indicate that no residue is present at that position, while slashes (/) indicate the presence of multiple extra residues (insertions not shown due to space constraints). When entire additional domains are inserted, this is indicated by abbreviated domain names in green, where "ENDO" indicates an endonuclease domain, and "DRR" indicates a DNA-recognition region. The locations of the conserved intein sequence blocks A, B, F, and G (see text) are indicated above the sequence.

The above figure is reprinted by permission from the Protein Society: Protein Sci (2007, 16, 1316-1328) copyright 2007.

Figure was selected by the author.