Abstract
Multi-functional enzymes are enzymes that perform multiple physiological functions. Characterization and identification of multi-functional enzymes are critical for communication and cooperation between different functions and pathways within a complex cellular system or between cells. In present study, we collected literature-reported 6,799 multi-functional enzymes and systematically characterized them in structural, functional, and evolutionary aspects. It was found that four physiochemical properties, that is, charge, polarizability, hydrophobicity, and solvent accessibility, are important for characterization of multi-functional enzymes. Accordingly, a combinational model of support vector machine and random forest model was constructed, based on which 6,956 potential novel multi-functional enzymes were successfully identified from the ENZYME database. Moreover, it was observed that multi-functional enzymes are non-evenly distributed in species, and that Bacteria have relatively more multi-functional enzymes than Archaebacteria and Eukaryota. Comparative analysis indicated that the multi-functional enzymes experienced a fluctuation of gene gain and loss during the evolution from S. cerevisiae to H. sapiens. Further pathway analyses indicated that a majority of multi-functional enzymes were well preserved in catalyzing several essential cellular processes, for example, metabolisms of carbohydrates, nucleotides, and amino acids. What’s more, a database of known multi-functional enzymes and a server for novel multi-functional enzyme prediction were also constructed for free access at http://bioinf.xmu.edu.cn/databases/MFEs/index.htm.
Highlights
In general concepts, multifunctional enzymes (MFEs) are enzymes that play multiple physiological roles
Promiscuous enzymes are characterized as enzymes of catalytic domains executing several functions, which can be further classified into three subtypes according to mechanisms of enzyme promiscuity: condition promiscuous enzymes, substrate promiscuous enzymes and catalytic promiscuous enzymes
Recognition of structural and physicochemical features that can properly describe this plasticity may be helpful for identification of MFEs by non-homology-based methods like Support vector machine (SVM) and Random forest (RF)
Summary
Multifunctional enzymes (MFEs) are enzymes that play multiple physiological roles. Sometimes, they are further specified as moonlighting enzymes or promiscuous enzymes [1,2,3,4]. Moonlighting enzymes are acknowledged to have at least a single catalytic domain and an additional noncatalytic domain. Both domains execute independent functions, and inactivation of either domain (e.g. by mutation) will not affect another domain [4]. Catalytic promiscuous enzymes can use the same active site to catalyze different biotransformations [5]. Promiscuous enzymes are annotated with more than one Enzyme Commission (EC) number, some promiscuous enzymes have only one given EC number but perform different activities [1]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
