PDBsum entry 2nx0

Oxygen storage/transport

PDB id: 2nx0

Contents

Protein chain

147 a.a. *

Ligands

SO4

HEM-_NO

Waters ×253

* Residue conservation analysis

PDB id:

2nx0

Name:

Oxygen storage/transport

Title:

Ferrous nitrosyl blackfin tuna myoglobin

Structure:

Myoglobin. Chain: a

Source:

Thunnus atlanticus. Blackfin tuna. Organism_taxid: 48168

Resolution:

0.95Å R-factor: 0.157 R-free: 0.178

Authors:

E.R.Schreiter,M.M.Rodriguez,A.Weichsel,W.R.Montfort,J.Bonaventura

Key ref:

E.R.Schreiter et al. (2007). S-nitrosylation-induced conformational change in blackfin tuna myoglobin. J Biol Chem, 282, 19773-19780. PubMed id: 17488722 DOI: 10.1074/jbc.M701363200

Date:

16-Nov-06 Release date: 08-May-07

Protein chain

P68190  (MYG_THUOR) -  Myoglobin from Thunnus orientalis

Seq: 147 a.a.

Struc: 147 a.a.*

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

Enzyme reactions

• Enzyme class 2: E.C.1.11.1.- - ?????
• Enzyme class 3: E.C.1.7.-.-

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.

DOI no: 10.1074/jbc.M701363200

J Biol Chem 282:19773-19780 (2007)

PubMed id: 17488722

S-nitrosylation-induced conformational change in blackfin tuna myoglobin.

E.R.Schreiter, M.M.Rodríguez, A.Weichsel, W.R.Montfort, J.Bonaventura.

ABSTRACT

S-nitrosylation is a post-translational protein modification that can alter the function of a variety of proteins. Despite the growing wealth of information that this modification may have important functional consequences, little is known about the structure of the moiety or its effect on protein tertiary structure. Here we report high-resolution x-ray crystal structures of S-nitrosylated and unmodified blackfin tuna myoglobin, which demonstrate that in vitro S-nitrosylation of this protein at the surface-exposed Cys-10 directly causes a reversible conformational change by "wedging" apart a helix and loop. Furthermore, we have demonstrated in solution and in a single crystal that reduction of the S-nitrosylated myoglobin with dithionite results in NO cleavage from the sulfur of Cys-10 and rebinding to the reduced heme iron, showing the reversibility of both the modification and the conformational changes. Finally, we report the 0.95-A structure of ferrous nitrosyl myoglobin, which provides an accurate structural view of the NO coordination geometry in the context of a globin heme pocket.

Selected figure(s)

Figure 1.
FIGURE 1. Electron density for S-nitrosylated Cys-10 of blackfin tuna myoglobin. Stereo view of the 2F[o] - F[c] electron density omit map for Cys-10 in S-nitrosylated myoglobin. The map is contoured at 1.0 and shown in blue mesh. The final refined model is shown as sticks colored by atom type. The three modeled conformations of Cys-10 are shown: conformations A and B are S-nitrosylated, whereas conformation C is not. All figures were produced using PyMOL.

Figure 4.
FIGURE 4. 0.95-Å ferrous nitrosyl myoglobin structure. A, stereo view of the nitrosyl heme and nearby side chains. The 2F[o] - F[c] electron density map for the heme group and amino acid side chains, contoured at 3.5 , is shown in brown mesh. The 2F[o] - F[c] electron density omit map for the NO group, contoured at 3.5 , is shown in blue mesh. The final refined model is represented as ball-and-stick colored by atom type. B, the same as A after rotation by 90° to give a "top" view.

The above figures are reprinted by permission from the ASBMB: J Biol Chem (2007, 282, 19773-19780) copyright 2007.

Figures were selected by an automated process.