1EFP

ELECTRON TRANSFER FLAVOPROTEIN (ETF) FROM PARACOCCUS DENITRIFICANS

1EFP の概要

• エントリーDOI: 10.2210/pdb1efp/pdb
• 分子名称: PROTEIN (ELECTRON TRANSFER FLAVOPROTEIN), FLAVIN-ADENINE DINUCLEOTIDE, ADENOSINE MONOPHOSPHATE, ... (5 entities in total)
• 機能のキーワード: electron transport, flavoprotein, glutaric acidemia type ii
• 由来する生物種: Paracoccus denitrificans; 詳細
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 118064.19

構造登録者

Roberts, D.L.,Salazar, D.,Fulmer, J.P.,Frerman, F.E.,Kim, J.J.-P. (登録日: 1998-12-18, 公開日: 1999-08-09, 最終更新日: 2023-08-09)

主引用文献

Roberts, D.L.,Salazar, D.,Fulmer, J.P.,Frerman, F.E.,Kim, J.J.
Crystal structure of Paracoccus denitrificans electron transfer flavoprotein: structural and electrostatic analysis of a conserved flavin binding domain.
Biochemistry, 38:1977-1989, 1999

PubMed Abstract: The crystal structure of electron transfer flavoprotein (ETF) from Paracoccus denitrificans was determined and refined to an R-factor of 19.3% at 2.6 A resolution. The overall fold is identical to that of the human enzyme, with the exception of a single loop region. Like the human structure, the structure of the P. denitrificans ETF is comprised of three distinct domains, two contributed by the alpha-subunit and the third from the beta-subunit. Close analysis of the structure reveals that the loop containing betaI63 is in part responsible for conferring the high specificity of AMP binding by the ETF protein. Using the sequence and structures of the human and P. denitrificans enzymes as models, a detailed sequence alignment has been constructed for several members of the ETF family, including sequences derived for the putative FixA and FixB proteins. From this alignment, it is evident that in all members of the ETF family the residues located in the immediate vicinity of the FAD cofactor are identical, with the exception of the substitution of serine and leucine residues in the W3A1 ETF protein for the human residues alphaT266 and betaY16, respectively. Mapping of ionic differences between the human and P. denitrificans ETF onto the structure identifies a surface that is electrostatically very similar between the two proteins, thus supporting a previous docking model between human ETF and pig medium-chain acyl-CoA dehydrogenase (MCAD). Analysis of the ionic strength dependence of the electron transfer reaction between either human or P. denitrificans ETF and MCAD demonstrates that the human ETF functions optimally at low ( approximately 10 mequiv) ionic strength, while P. denitrificans ETF is a better electron acceptor at higher (>75 mequiv) ionic strength. This suggests that the electrostatic surface potential of the two proteins is very different and is consistent with the difference in isoelectric points between the proteins. Analysis of the electrostatic potentials of the human and P. denitrificans ETFs reveals that the P. denitrificans ETF is more negatively charged. This excess negative charge may contribute to the difference in redox potentials between the two ETF flavoproteins and suggests an explanation for the opposing ionic strength dependencies for the reaction of MCAD with the two ETFs. Furthermore, by analysis of a model of the previously described human-P. denitrificans chimeric ETF protein, it is possible to identify one region of ETF that participates in docking with ETF-ubiquinone oxidoreductase, the physiological electron acceptor for ETF.

PubMed: 10026281
DOI: 10.1021/bi9820917

実験手法

X-RAY DIFFRACTION (2.6 Å)