Abstract Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), the key CO 2 -fixing enzyme in photosynthesis, is notorious for its low carboxylation. We report a highly active and assembly-competent Form II Rubisco from endosymbiont of deep-sea tubeworm Riftia pachyptila (RPE Rubisco), which shows 50.5% higher carboxylation efficiency than that high functioning Synechococcus sp. PCC7002 (7...

Ribulose 1,5-bisphosphate carboxylase/oxygenase (rubisco) activase protein was purified from spinach leaves by ammonium sulfate precipitation and ion exchange fast protein liquid chromatography. This resulted in 48-fold purification with 70% recovery of activity and yielded up to 18 milligrams of rubisco activase protein from 100 grams of leaves. Based on these figures, the protein comprised ap...

the effects of drought stress and exogenous abscisic acid on the expression of ribulose-1, 5-bisphosphate carboxyiase/oxygenase activase (rubisco activase) were examined in wheat (triticum aestivuml.). in response to water stress and abscisic acid, both the levels of endogenous abscisic acid and rubiscoactivase increased in the leaves. immunoblot analysis showed that both drought stress and abs...

The enzyme-catalyzed activation of ribulosebisphosphate carboxylase/oxygenase (rubisco) was investigated in an illuminated reconstituted system containing thylakoid membranes, rubisco, ribulosebisphosphate (RuBP), MgCl(2), carbonic anhydrase, catalase, the artificial electron acceptor pyocyanine, and partially purified rubisco activase. Optimal conditions for light-induced rubisco activation we...

Rubisco activity can be measured using gas exchange (in vivo) or using in vitro methods. Commonly in vitro methods yield activities that are less than those obtained in vivo. Rubisco activity was measured both in vivo and in vitro using a spectrophotometric technique in mature Pinus taeda L. (loblolly pine) trees grown using free-air CO2 enrichment in elevated (56 Pa) and current (36 Pa) pCO2. ...

We quantified the ozone impact on levels of Zea mays L. cv. Chambord mRNAs encoding C4-phosphoenolpyruvate carboxylase (C4-PEPc), ribulose-l,5-bisphosphate carboxylase/oxygenase small and large subunits (Rubisco-SSU and Rubisco-LSU, respectively) and Rubisco activase (RCA) using real-time RT-PCR. Foliar pigment content, PEPc and Rubisco protein amounts were simultaneously determined. Two experi...

Rubisco activase is an AAA(+) protein, a superfamily with members that use a "Sensor 2" domain for substrate recognition. To determine whether the analogous domain of activase is involved in recognition of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco, EC 4.1.1.39), two chimeric activases were constructed, interchanging a Sensor 2-containing region between activases from spinach and ...

Previous studies have shown that inhibition of photosynthesis by moderate heat stress is a consequence of Rubisco deactivation, caused in part by the thermal instability of Rubisco activase. This involvement of Rubisco activase was confirmed in heat stress and recovery experiments using transgenic Arabidopsis plants. Compared with wild-type plants, photosynthesis, the effective quantum yield of...

The importance of ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco, EC 4.1.1.39) would be difficult to exaggerate, because it provides the only quantitatively significant link between the pools of inorganic and organic carbon in biosphere. The major reason for paying so much attention to rubisco steams from the fact that it catalyzes the rate-limiting step in photosynthesis. In 1971 it ...

A simple, improved model of Rubisco synthesis and degradation in cereal leaves is developed using data obtained over the leaf lifespan to return maximum likelihood values for Rubisco proteolysis and biosynthesis. It assumes that the time course of leaf Rubisco content can be described using a log-normal curve, and degradation of the Rubisco pool occurs exponentially. Curve parameters give an in...