Crystal structure of VmoLac, a tentative quorum quenching lactonase from the extremophilic crenarchaeon Vulcanisaeta moutnovskia
Authors: Charlotte Champion
Janek Bzdrenga
Julien Hiblot
Mikael Elias
Eric Chabriere
Journal: Scientific Reports (2015)
Discipline: Multidisciplinary
Keywords: Phosphotriesterase-Like Lactonases; Vulcanisaeta moutnovskia; VmoLac; hyperthermophilic; lactonase
Affiliations: URMITE UMR CNRS-IRD 6236, IFR48, Faculté de Médecine et de Pharmacie, Université de la Méditerranée, Marseille, France., University of Minnesota, Department of Biochemistry, Molecular Biology and Biophysics &Biotechnology Institute, St. Paul, MN 55108, USA.

Abstract:  A new representative of the Phosphotriesterase-Like Lactonases (PLLs) family from the hyperthermophilic crenarchaeon Vulcanisaeta moutnovskia has been characterized and crystallized. VmoLac is a native, proficient lactonase with promiscuous, low phosphotriesterase activity. VmoLac therefore represents an interesting candidate for engineering studies, with the aim of developing an efficient bacterial quorum-quenching agent. Here, we provide an extensive biochemical and kinetic characterization of VmoLac and describe the X-ray structures of the enzyme bound to a fatty acid and to its cognate substrate 3-oxo-C10 AHL (Acyl-Homoserine Lactone). The structures highlight possible structural determinants that may be involved in its extreme thermal stability (Tm = 128 °C). Moreover, the structure reveals that the substrate binding mode of VmoLac significantly differs from those of its close homologues, possibly explaining the substrate specificity of the enzyme. Finally, we describe the specific interactions between the enzyme and its substrate, and discuss the possible lactone hydrolysis mechanism of VmoLac. 

Retracted: No

PubPeer comments:
 In this paper, a Phosphotriesterase-Like Lactonase (PLL) protein is described, isolated from the hyperthermophilic crenarchaeon Vulcanisaeta moutnovskia. The paper concludes with Due to its dual catalytic activities, i.e., lactonase and phosphotriesterase, VmoLac could represent an interesting target for in vitro evolution with the aims of developing a quorum quenching agent and an efficient organophosphorous biodecontaminant. In addition, the paper includes this sentence: The authors declare no competing financial interests. Yet, two patent applications filed by some of the authors on this paper appear to be relevant. Both were filed before this manuscript was submitted (24 October 2014). * MUTATED HYPERTHERMOPHILC PHOSPHOTRIESTERASES AND THEIR USES - US Patent 8,372,618B2, PCT filed April 2008, patent granted February 12, 2013. https: patentimages.storage.googleapis.com 3d 31 8e 4b2e8143b7fe9d US8372618.pdf - This patent describes the use of hyperthermophilic phosphotriesterases for the decontamination of organophosphorus compounds . * SULFOLOBAL PHOSPHOTRIESTERASE -LIKE (PLL) LACTONASES ACTIVITY HAVING ENHANCED PROPERTIES AND THE USES THEREOF - US Patent 10,072,252B2, PCT filed April 14, 2014. https: patents.google.com patent US10072252B2 en - This patent describes compositions including the mutated hyperthermophilic PTE and the uses thereof, notably as bioscavenger of organophosphate compounds or as quorum quencher of the bacteria using lactones to communicate. ![file] ![file] Could the authors please clarify why these (provisional) patent applications were not disclosed? , 
 Dear Dr. Bik, This is the fourth weak comment that you make today on pubpeer on our research articles, and this could be seen as targeted harassment. 1. The first patent that you are referring to, focuses on and protects specific mutants of SsoPox (the patented mutants of Ssopox = the phosphotriesterases), NOT the wild-type VmoLac enzyme depicted in this paper. None of the patented mutant enzymes are studied in this paper or are remotely relevant to this paper. It is a different enzyme = NOT the same subject of study. Additionally, the main focus of the paper resides in VmoLac s quorum quenching activity, not its organophosphorus compounds degrading activity (emphasis of the patent). 2. The second patent you are referring to protects mutants of SsoPox  with enhanced properties , a completely different set of enzymes than the wild-type VmoLac enzyme used in this study! Not the same subject of study either. 3. As mentioned in my previous responses to your other comments, for the cases where the patent may relate to the subject of the research article, which is not the case here: one can regret that scientific publications did not typically disclose disclose patents related to the subject of the publication until recently, unless it constituted a competing financial interest (i.e. a license, royalties, etc; see The Duty to Disclose Patent Rights, by R. M Lebovitz, 2007). Accordingly, there were journal policies (and possibly still today), that did not systematically require the disclosure of patents related to the subject of the publication. (See The Duty to Disclose Patent Rights, by R. M Lebovitz, 2007). Quote: Scientific research publications do not, as a rule, disclose the existence of patent rights associated with the subject matter of the publication.  Thanks much, Mikael Elias , 
 I thank Dr. Elias for his comments regarding the patent. However, the authors also did not disclose that they are founders of a biotech company called  Gene GreenTK , which was founded in 2013, thus also predating the submission of this paper. The company s expertise appears very relevant to the enzyme described in the paper. Some quotes from their website https: www.gene-greentk.com (archived: https: archive.is 6Gr1R) : *  The work of G G is dedicated to the development and engineering of enzymes isolated from microorganisms living in extreme environments. *  We develop enzymes that ally both perfomance [sic] and stability. Coming straight from extreme environments and produced by hyperthermophilic microorganisms. *  Bacteria use chemical signals to communicate and coordinate behaviors including virulence and biofilm formation. Our technology interrupts bacterial communication by degrading signal molecules thereby preventing bacteria from forming biofilms and to start a virulence program. *  Anti-virulence and anti-biofilm for the development of novel medical devices, anti-fouling paintings or coatings and biobased materials ![file] , 
 Dear Dr. Bik, I have explained above that the subject matter is not related. I am not going to re-iterate it. The paper focuses on a wild type molecule that (i) cannot be patented and (ii) is not a focus of the startup company (as explained above). Therefore, neither the above mentioned patent nor the startup company are or can be affected by this publication, and vice versa. ,