o-Succinylbenzoate—CoA ligase (EC 6.2.1.26), encoded from the menE gene in Escherichia coli, catalyzes the fifth reaction in the synthesis of menaquinone (vitamin K2). This pathway is called 1, 4-dihydroxy-2-naphthoate biosynthesis I.[1] Vitamin K is a quinone that serves as an electron transporter during anaerobic respiration. This process of anaerobic respiration allows the bacteria to generate the energy required to survive.
| o-Succinylbenzoate—CoA ligase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 A cartoon representation of O-succinylbenzoate Co-A ligase of Staphylococcus aureus (strain N315). The different subunits are shown in different colors. | |||||||||
| Identifiers | |||||||||
| EC no. | 6.2.1.26 | ||||||||
| CAS no. | 72506-70-8 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| |||||||||
Background edit
The systematic name for the MenE enzyme is 2-succinylbenzoate: CoA ligase (AMP-forming). Other names for this enzyme include: o-succinylbenzoate-CoA synthase; o-succinylbenzoyl-coenzyme A synthetase; OSB-CoA synthetase; OSB: CoA ligase; synthetase, and o-succinylbenzoyle coenzyme A. The EC number is 6.2.1.26. MenE belongs to the ligase enzyme family, or class 6.
In the presence of 0.5mM of Ca(2+), K(+), Na(+), and Zn(2+) the enzyme activity was increased twofold. In the presence of .5 mM of Co(2+) and Mn(2+) the enzyme activity was increased fourfold. Mg(2+) is the ion that increases the enzyme activity the most. With .5 mM of Mg(2+) enzyme activity was increased sixfold. Inhibitors of this enzyme include diethylprocarbonate, Fe(2+), Hg(2+), and Mg(2+) (above 1mM).[2]
The maximum specific enzymatic activity is 3.2 micromol/min/mg. The optimum pH is 7.5. The maximum pH is 8. The optimum temperature is 30 degrees Celsius and the maximum temperature is 40 degrees Celsius. The molecular weight of o-succinylbenzoate CoA ligase is 185000 Da or 185 kDa. This enzyme is a tetramer, meaning it has four subunits in its quaternary structure.[2]
The PDB accession code is 3ipl. This is the crystal structure for o-succinylbenzoate CoA ligase in Staphylococcus aureus (strain N315) because the structure for E. coli has not been crystallized as of yet.[3]
Pathway edit
The pathway o-succinylbenzoate CoA ligase belongs to is called 1, 4-dihydroxy-2-napthoate biosynthesis I. Other organisms that contain this pathway are eukaryotic bacteria such as Bacillus anthracis.[4] Organisms that contain a pathway similar to this include Arabidopsis thaliana (gene AAE14),[5] Mycobacterium phlei,[6] and Synechocystis sp. (gene PCC 6803).[7] The reason for the difference in pathways is due to the varying functions of Vitamin K. Eukaryotic bacteria use vitamin K II while other organisms use vitamin K I. Other pathways that include o-succinylbenzoate CoA ligase include 1, 4-diydroxy-2-naphthoate biosynthesis II (i.e. in Arabidopsis thaliana), biosynthesis of secondary metabolites, metabolic pathways, ubiquinone, and other terpenoid-quinone biosynthesis. In Bacillus anthracis this enzyme is a target of potential antibiotic discovery.
Reaction edit
The reaction in vitamin K synthesis that includes MenE is as follows:
ATP + 2-succinylbenzoate + CoA = AMP + diphosphate + 4-(2-carboxyphenyl)-4-oxobutanoyl-CoA
The substrates of this reaction are ATP, CoA, and 2-succinylbenzoate. The cofactors are ATP and CoA. The products are AMP, diphosphate, and 4-(2-carboxyphenyl)-4-oxobutanoyl-CoA.[8]
References edit
- ^ van Oostende, Widhalm, Furt, Ducluzeau, Basset (2011). Phylloquinone (Vitamin K1): function, enzymes and genes. Advances in Botanical Research: Academic Press (Amsterdam). pp. 229–61.
{{cite book}}: CS1 maint: multiple names: authors list (link) - ^ a b Kwon O, Bhattacharyya DK, Meganathan R (December 1996). "Menaquinone (vitamin K2) biosynthesis: overexpression, purification, and properties of o-succinylbenzoyl-coenzyme A synthetase from Escherichia coli". Journal of Bacteriology. 178 (23): 6778–81. doi:10.1128/jb.178.23.6778-6781.1996. PMC 178575. PMID 8955296.
- ^ Patskovsky, Toro, Dickey, Sauder, Chang, Burley, Almo. "Crystal structure of o-succinylbenzoic acid-CoA ligase from Staphylococcus aureus". PDB. RCSB. Retrieved 6 December 2014.
{{cite web}}: CS1 maint: multiple names: authors list (link) - ^ Tian Y, Suk DH, Cai F, Crich D, Mesecar AD (November 2008). "Bacillus anthracis o-succinylbenzoyl-CoA synthetase: reaction kinetics and a novel inhibitor mimicking its reaction intermediate". Biochemistry. 47 (47): 12434–47. doi:10.1021/bi801311d. PMC 2710618. PMID 18973344.
- ^ Kim HU, van Oostende C, Basset GJ, Browse J (April 2008). "The AAE14 gene encodes the Arabidopsis o-succinylbenzoyl-CoA ligase that is essential for phylloquinone synthesis and photosystem-I function". The Plant Journal. 54 (2): 272–83. doi:10.1111/j.1365-313X.2008.03416.x. PMID 18208520.
- ^ Sieweke HJ, Leistner E (August 1991). "o-Succinylbenzoate: coenzyme A ligase, an enzyme involved in menaquinone (vitamin K2) biosynthesis, displays broad specificity". Zeitschrift für Naturforschung C. 46 (7–8): 585–90. doi:10.1515/znc-1991-7-814. PMID 1663748. S2CID 12789671.
- ^ Johnson, Naithani, Stewart Jr., Zybailov, Jones, Golbeck, Chitnis (6 March 2003). "The menD and menE homologs code for 2-succinyl-6-hydroxyl-2,4-cyclohexadiene-1-carboxylate synthase and O-succinylbenzoic acid-CoA synthase in the phylloquinone biosynthetic pathway of Synechocystis sp. PCC 6803". Biochimica et Biophysica Acta (BBA) - Bioenergetics. 1557 (1–3): 67–76. doi:10.1016/S0005-2728(02)00396-1. PMID 12615349.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Kolkmann R, Leistner E (December 1987). "4-(2'-Carboxyphenyl)-4-oxobutyryl coenzyme A ester, an intermediate in vitamin K2 (menaquinone) biosynthesis". Zeitschrift für Naturforschung C. 42 (11–12): 1207–14. doi:10.1515/znc-1987-11-1212. PMID 2966501. S2CID 41701934.
