Proteomic analysis of organic sulfur compound utilisation in Advenella mimigardefordensis strain DPN7T.

Christina Meinert,Jessica Beyert,Alexander Steinbüchel,Viktoria Heine,Birgit Voigt,Jan Hendrik Wübbeler,Katharina Riedel,Sina Schmidl,Ulrike Brandt

doi:10.1371/journal.pone.0174256

Christina Meinert, Jessica Beyert + Show 7 more

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https://doi.org/10.1371/journal.pone.0174256

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Abstract

2-Mercaptosuccinate (MS) and 3,3´-ditiodipropionate (DTDP) were discussed as precursor substance for production of polythioesters (PTE). Therefore, degradation of MS and DTDP was investigated in Advenella mimigardefordensis strain DPN7T, applying differential proteomic analysis, gene deletion and enzyme assays. Protein extracts of cells cultivated with MS, DTDP or 3-sulfinopropionic acid (SP) were compared with those cultivated with propionate (P) and/or succinate (S). The chaperone DnaK (ratio DTDP/P 9.2, 3SP/P 4.0, MS/S 6.1, DTDP/S 6.2) and a Do-like serine protease (DegP) were increased during utilization of all organic sulfur compounds. Furthermore, a putative bacterioferritin (locus tag MIM_c12960) showed high abundance (ratio DTDP/P 5.3, 3SP/P 3.2, MS/S 4.8, DTDP/S 3.9) and is probably involved in a thiol-specific stress response. The deletion of two genes encoding transcriptional regulators (LysR (MIM_c31370) and Xre (MIM_c31360)) in the close proximity of the relevant genes of DTDP catabolism (acdA, mdo and the genes encoding the enzymes of the methylcitric acid cycle; prpC,acnD, prpF and prpB) showed that these two regulators are essential for growth of A. mimigardefordensis strain DPN7T with DTDP and that they most probably regulate transcription of genes mandatory for this catabolic pathway. Furthermore, proteome analysis revealed a high abundance (ratio MS/S 10.9) of a hypothetical cupin-2-domain containing protein (MIM_c37420). This protein shows an amino acid sequence similarity of 60% to a newly identified MS dioxygenase from Variovorax paradoxus strain B4. Deletion of the gene and the adjacently located transcriptional regulator LysR, as well as heterologous expression of MIM_c37420, the putative mercaptosuccinate dioxygenase (Msdo) from A. mimigardefordensis, showed that this protein is the key enzyme of MS degradation in A. mimigardefordensis strain DPN7T (KM 0.2 mM, specific activity 17.1 μmol mg-1 min-1) and is controlled by LysR (MIM_c37410).

Highlights

Advenella mimigardefordensis strain DPN7T was first described by Wubbeler et al in 2006 [1]
Cells were cultivated in mineral salt medium (MSM) with (i) propionate (P), the final degradation product of dithiodipropionic acid (DTDP) catabolism, (ii) 3-sulfinopropionic acid (3SP), an intermediate of DTDP catabolism, or (iii) DTDP (Fig 2A, 2B and 2C)
This study focuses on proteins that showed an at least 3-fold higher quantity during cultivation with DTDP and MS in comparison to the corresponding controls, propionate and succinate, respectively

Summary

Introduction

Advenella mimigardefordensis strain DPN7T was first described by Wubbeler et al in 2006 [1] It was designated as Tetrathiobacter mimigardefordensis and in 2009 reclassified to the genus Advenella, which currently consists of five species [2,3,4,5,6,7]. Strains of this genus belong to the family Alcaligenaceae and have been detected in a variety of habitats [8]. This is interesting as both compounds were discussed as precursor substrates for polythioester (PTE) production [10]

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