PDBsum entry 2v5v

Electron transport

PDB id: 2v5v

Contents

Protein chains

169 a.a. *

Ligands

FMN ×2

Metals

_MG

Waters ×236

* Residue conservation analysis

PDB id:

2v5v

Name:

Electron transport

Title:

W57e flavodoxin from anabaena

Structure:

Flavodoxin. Chain: a, b. Engineered: yes. Mutation: yes

Source:

Anabaena sp.. Organism_taxid: 1168. Strain: pcc 7119. Expressed in: escherichia coli. Expression_system_taxid: 562. Expression_system_variant: tg1.

Resolution:

1.88Å R-factor: 0.184 R-free: 0.224

Authors:

B.Herguedas,M.Martinez-Julvez,I.Perez-Dorado,G.Goni,M.Medina, J.A.Hermoso

Key ref:

S.Frago et al. (2007). Tuning of the FMN binding and oxido-reduction properties by neighboring side chains in Anabaena flavodoxin. Arch Biochem Biophys, 467, 206-217. PubMed id: 17904516

Date:

10-Jul-07 Release date: 16-Oct-07

Protein chains

P0A3E0  (FLAV_NOSSO) -  Flavodoxin from Nostoc sp. (strain ATCC 29151 / PCC 7119)

Seq: 170 a.a.

Struc: 169 a.a.*

* PDB and UniProt seqs differ at 2 residue positions (black crosses)

Arch Biochem Biophys 467:206-217 (2007)

PubMed id: 17904516

Tuning of the FMN binding and oxido-reduction properties by neighboring side chains in Anabaena flavodoxin.

S.Frago, G.Goñi, B.Herguedas, J.R.Peregrina, A.Serrano, I.Perez-Dorado, R.Molina, C.Gómez-Moreno, J.A.Hermoso, M.Martínez-Júlvez, S.G.Mayhew, M.Medina.

ABSTRACT

Contribution of three regions (phosphate-binding, 50's and 90's loops) of Anabaena apoflavodoxin to FMN binding and reduction potential was studied. Thr12 and Glu16 did not influence FMN redox properties, but Thr12 played a role in FMN binding. Replacement of Trp57 with Glu, Lys or Arg moderately shifted E(ox/sq) and E(sq/hq) and altered the energetic of the FMN redox states binding profile. Our data indicate that the side chain of position 57 does not modulate E(ox/sq) by aromatic stacking or solvent exclusion, but rather by influencing the relative strength of the H-bond between the N(5) of the flavin and the Asn58-Ile59 bond. A correlation was observed between the isoalloxazine increase in solvent accessibility and less negative E(sq/hq). Moreover, E(sq/hq) became less negative as positively charged residues were added near to the isoalloxazine. Ile59 and Ile92 were simultaneously mutated to Ala or Glu. These mutations impaired FMN binding, while shifting E(sq/hq) to less negative values and E(ox/sq) to more negative. These effects are discussed on the bases of the X-ray structures of some of the Fld mutants, suggesting that in Anabaena Fld the structural control of both electron transfer steps is much more subtle than in other Flds.