Pyridoxine 5'-phosphate oxidases (PNPOxs) are known to catalyse the terminal step in pyridoxal 5'-phosphate biosynthesis in a flavin mononucleotide-dependent manner in humans and Escherichia coli. Recent reports of a putative PNPOx from Mycobacterium tuberculosis, Rv1155, suggest that the cofactor or catalytic mechanism may differ in Mycobacterium species. To investigate this, a putative PNPOx from M. smegmatis, Msmeg_3380, has been cloned. This enzyme has been recombinantly expressed in E. coli and purified to homogeneity. Good-quality crystals of selenomethionine-substituted Msmeg_3380 were obtained by the hanging-drop vapour-diffusion technique and diffracted to 1.2 A using synchrotron radiation.
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http://dx.doi.org/10.1107/S1744309108011512 | DOI Listing |
Adv Sci (Weinh)
December 2024
Nanjing Hospital of Chinese Medicine affiliated to Nanjing University of Chinese Medicine, Nanjing, 210022, China.
Multiple myeloma (MM) is a cancer of plasma cells caused by abnormal gene expression and interactions within the bone marrow (BM) niche. The BM environment significantly influences the progression of MM. Celastrol, a natural compound derived from traditional Chinese medicine, exhibits significant anticancer effects.
View Article and Find Full Text PDFBiosystems
October 2023
Cell Systems Modelling Group, Oxford Brookes University, Oxford, OX3 0BP, UK. Electronic address:
We describe a novel algorithm, 'LPEM', that given a steady-state flux vector from a (possibly genome-scale) metabolic model, decomposes that vector into a set of weighted elementary modes such that the sum of these elementary modes is equal to the original flux vector. We apply the algorithm to a genome scale metabolic model of the human pathogen Campylobacter jejuni. This organism is unusual in that it has an absolute growth requirement for oxygen, despite being able to operate the electron transport chain anaerobically.
View Article and Find Full Text PDFFEBS J
November 2024
Dipartimento di Scienze Biochimiche "A. Rossi Fanelli", Sapienza Università di Roma, Italy.
Pyridoxal 5'-phosphate (PLP), the catalytically active form of vitamin B, acts as a cofactor in many metabolic processes. In humans, PLP is produced in the reactions catalysed by pyridox(am)ine 5'-phosphate oxidase (PNPO) and pyridoxal kinase (PDXK). Both PNPO and PDXK are involved in cancer progression of many tumours.
View Article and Find Full Text PDFNat Metab
June 2024
Department of Medical Biochemistry, Tohoku University Graduate School of Medicine, Sendai, Japan.
Oxygen is critical for all metazoan organisms on the earth and impacts various biological processes in physiological and pathological conditions. While oxygen-sensing systems inducing acute hypoxic responses, including the hypoxia-inducible factor pathway, have been identified, those operating in prolonged hypoxia remain to be elucidated. Here we show that pyridoxine 5'-phosphate oxidase (PNPO), which catalyses bioactivation of vitamin B6, serves as an oxygen sensor and regulates lysosomal activity in macrophages.
View Article and Find Full Text PDFApoptosis
October 2024
Research Center for Clinical Medicine, Jinshan Hospital, Fudan University, 1508 Longhang Road, Shanghai, 201508, China.
Our previous study showed that pyridoxine 5'-phosphate oxidase (PNPO) is a tissue biomarker of ovarian cancer (OC) and has a prognostic implication but detailed mechanisms remain unclear. The current study focused on PNPO-regulated lysosome/autophagy-mediated cellular processes and the potential role of PNPO in chemoresistance. We found that PNPO was overexpressed in OC cells and was a prognostic factor in OC patients.
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