|
type |
Journal Article |
authors |
Miller DV, Wang Y, Xu H, Harich K, White RH. |
title |
Biosynthesis of the 5-(aminomethyl)-3-furanmethanol moiety of methanofuran |
journal |
Biochemistry |
Activity |
2.6.1.108 |
Family |
2.6.1.108 |
sel |
selected |
ui |
24977328 |
year |
(2014) |
volume |
53 |
number |
28 |
pages |
4635-47 |
| |
keywords |
doi: 10.1021/bi500615p |
abstract |
We have established the biosynthetic pathway and the associated genes for the biosynthesis of the 5-(aminomethyl)-3-furanmethanol (F1) moiety of methanofuran in the methanogenic archaeon Methanocaldococcus jannaschii. The recombinant enzyme, derived from the MJ1099 gene, was shown to readily condense glyceraldehyde-3-phosphate (Ga-3P) and dihydroxyacetone-P (DHAP) to form 4-hydroxymethyl-2-furancarboxaldehyde phosphate (4-HFC-P). The recombinant purified PLP-dependent aminotransferase, derived from the MJ0684 gene, was found to be specific for catalyzing the transamination reaction between 4-HFC-P and 15N-alanine to produce 15N-F1-P and pyruvate. To confirm these results in cell extracts sensitive analytical methods were developed for the LC-UV-ESI-MS analysis of F1 as a 7-nitrobenzofurazan (NBD) derivative. This method has allowed for the quantitation of trace amounts of F1 and 5-(aminomethyl)-3-furanmethanol-P (F1-P) in cell extracts and the measurement of the incorporation of stable isotopically labeled precursors into F1. Incubation of cell extracts with [1, 2, 3-13C3]-pyruvate and DHAP, 4-(2H2-hydroxymethyl)-2-furancarboxylic acid phosphate (4-HFCA-P) or 4-(2H2-hydroxymethyl)-2-furancarboxaldehyde phosphate (4-HFC-P) were found to each be incorporated into F1-P. 4-HFCA-P and 4-HFC-P were confirmed in cell extracts after removal of the phosphate. The low incorporation of [1, 2, 3-13C3]-pyruvate into F1-P in these experiments is explained since the labeled pyruvate must first be converted into Ga-3-P through gluconeogenesis before incorporation into 4-HFC-P. Cell extracts incubated with 4-HFC-P and a mixture of 15N-aspartate, 15N-glutamate, and 15N-alanine produced 15N-F1-P. We also demonstrated that aqueous solutions of methylglyoxal or pyruvate heated with dihydroxyacetone led to the formation of 4-HFC and 4-HFCA suggesting a possible prebiotic route to this moiety of methanofuran. |
last changed |
2017/09/05 10:18 |
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