Iron—sulfur cluster‐containing l‐serine dehydratase from Peptostreptococcus asaccharolyticus: Correlation of the cluster type with enzymatic activity

FEBS Letters

Albracht, S.P.J.²  Buckel, W.¹  Hofmeister, A.E.M.¹ 

[1] Laboratorium für Mikrobiologie des Fachbereichs Biologie der Philipps- Universität Marburg, Karl-von-Frisch-Str, D-35032 Marburg, Germany;E.C. Slater Institute, BioCentrum Amsterdam, Plantage Muidergracht 12 NL-1018 TV Amsterdam, The Netherlands

关键词: l-Serine dehydratase;    Electron paramagnetic resonance;    [3Fe–4S]+ cluster;    [4Fe–4S]2+ cluster;    Non-redox iron—sulfur protein;    Peptostreptococcus asaccharolyticus;   

DOI  :  10.1016/0014-5793(94)00901-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Investigations were performed with regard to the function of the iron—sulfur cluster of l-serine dehydratase from Peptostreptococcus asaccharolyticus, an enzyme which is novel in the class of deaminating hydro-lyases in that it lacks pyridoxal-5′-phosphate. Anaerobically purified l-serine dehydratase from P. asaccharolyticus revealed EPR spectra characteristic of a [3Fe–4S]⁺ cluster constituting 1% of the total enzyme concentration. Upon incubation of the enzyme under air the intensity of the [3Fe–4S]⁺ signal increased correlating with the loss of enzymatic activity. Addition of l-serine prevented this. Hence, active l-serine dehydratase probably contains a diamagnetic [4Fe–4S]²⁺ cluster which is converted by oxidation and loss of one iron ion to a paramagnetic [3Fe–4S]⁺ cluster, resulting in inactivation of the enzyme. In analogy to the mechanism elucidated for aconitase, it is proposed that l-serine is coordinated via its hydroxyl and carboxyl groups to the labile iron atom of the [4Fe–4S]²⁺ cluster.

【 授权许可】

Unknown