The objective of the present work was to determine the impact of nitrogen deficiency on proline metabolism in French Bean plants (Phaseolus vulgaris L. cv. Strike). The nitrogen was applied to the nutrient solution in the form of NH4NO3 at 1.45 mM (N1), 2.90 mM (N2) and 5.80 mM (N3, optimal level). Our results indicate N deficiency is characterised by a decline in proline accumulation both in t...

L-Proline is one of Mother Nature's cryoprotectants. Plants and yeast accumulate proline under freeze-induced stress and the use of proline in the cryopreservation of biological samples is well established. Here, it is shown that L-proline is also a useful cryoprotectant for protein crystallography. Proline was used to prepare crystals of lysozyme, xylose isomerase, histidine acid phosphatase a...

L-Proline is oxidized to pyrroline-5-carboxylic acid in intact plant mitochondria by a proline dehydrogenase (EC 1.4.3) that is bound to the matrix side of the inner mitochondrial membrane (TE Elthon, CR Stewart [1981] Plant Physiol 67: 780-784). This investigation reports the first solubilization of the L-proline dehydrogenase (PDH) from plant mitochondria. The supernatant from NP-40-treated e...

Aim. Analysis of physiological and biochemical characteristics genetically modified wheat with partially suppressed activity the proline dehydrogenase gene. Methods. Determination (PDH) activity, free L-proline (Pro); carbohydrate content (sucrose fructose). Results. It was established that under conditions water deficit in plants integrated elements forming double-stranded RNA suppressor pdh g...

L-Proline can be used by Bacillus subtilis as a sole source of carbon or nitrogen. We traced L-proline utilization genetically to the putBCP (ycgMNO) locus. The putBCP gene cluster encodes a high-affinity proline transporter (PutP) and two enzymes, the proline dehydrogenase PutB and the Δ(1)-pyrroline-5-carboxylate dehydrogenase PutC, which jointly catabolize L-proline to L-glutamate. Northern ...

The flavoenzyme proline dehydrogenase catalyzes the first step of proline catabolism, the oxidation of proline to pyrroline-5-carboxylate. Here we report the first crystal structure of an irreversibly inactivated proline dehydrogenase. The 1.9 A resolution structure of Thermus thermophilus proline dehydrogenase inactivated by the mechanism-based inhibitor N-propargylglycine shows that N5 of the...

Proline metabolism is an important pathway that has relevance in several cellular functions such as redox balance, apoptosis, and cell survival. Results from different groups have indicated that substrate channeling of proline metabolic intermediates may be a critical mechanism. One intermediate is pyrroline-5-carboxylate (P5C), which upon hydrolysis opens to glutamic semialdehyde (GSA). Recent...

We have investigated the basis for an increased level of proline dehydrogenase activity, the most prominent phenotype displayed by a mutant of Escherichia coli lacking leucyl-, phenylalanyl-tRNA:protein transferase. A dehydrogenase preparation of approximately 95% purity from the transferaseless mutant contained glycine, which is not an acceptor determinant in the transfer reaction, as the sole...

Based on localization and high activities of pyrroline-5-carboxylate reductase and proline dehydrogenase activities in soybean nodules, we previously suggested two major roles for pyrroline-5-carboxylate reductase in addition to the production of the considerable quantity of proline needed for biosynthesis; namely, transfer of energy to the location of biological N(2) fixation, and production o...