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RuBisCO is the most abundant enzyme on earth; it regulates the organic carbon cycle in the biosphere. Studying its structural evolution will help to develop new strategies of genetic improvement in order to increase food production and mitigate CO2 emissions. In the present work, we evaluate how the evolution of sequence and structure among isoforms I, II and III of RuBisCO defines their intrinsic flexibility and residue-residue interactions. To do this, we used a multilevel approach based on phylogenetic inferences, multiple sequence alignment, normal mode analysis, and molecular dynamics. Our results show that the three isoforms exhibit greater fluctuation in the loop between αB and βC, and also present a positive correlation with loop 6, an important region for enzymatic activity because it regulates RuBisCO conformational states. Likewise, an increase in the flexibility of the loop structure between αB and βC, as well as Lys330 (form II) and Lys322 (form III) of loop 6, is important to increase photosynthetic efficiency. Thus, the cross-correlation dynamics analysis showed changes in the direction of movement of the secondary structures in the three isoforms. Finally, key amino acid residues related to the flexibility of the RuBisCO structure were indicated, providing important information for its enzymatic engineering.

A�������. Polylepis (Rosaceae) is the dominant tree genus in High-Andean forest ecosystems. These ecosystems are severely threatened, but li�le is known about their structure and functioning. We provide the first reports of the dasometric structure and spatial distribution of eight forests of Polylepis canoi, P. flavipila and P. rodolfovasquezii in the Central Peruvian Andes as fundamental information for management and conservation policies. We sampled all individuals ≥1 cm of diameter at ground level (DGL) in 20 plots of 10x10 m in each forest, and measured total height (TH) and DGL. Also, we mapped the spatial distribution of the individuals in two plots of 30x30 m (X and Y axes). We found differences in the dasometric structure between forests of the same species, which, in some cases, were associated with climate, soil or elevation variables. However, no well-defined pa�ern was found. The allometric relationships of the linear and non-linear models did not differ widely with respect to the R 2 nor to the Akaike (AIC) scores, indicating that the forests did not show a saturation of tree height with increasing diameter. In the P. canoi forests, individuals with diameters ≥10 cm were the most abundant. In contrast, the forests of P. rodolfo-vasquezii showed a predominance of individuals with diameters ≤10 cm, whereas P. flavipila presented an altered structure with no relationship between DGL and TH in one of the evaluated forests. The analysis of spatial distribution according to the Ripley's K function on a small scale revealed that P. flavipila and P. canoi presented random pa�erns, whereas P. rodolfo-vasquezii showed an aggregate pa�ern. Finally, our results showed that even forests of the same species have different dasometric structures, whereas spatial pa�erns differ only between species. So, caution must be taken when extrapolating information between species or forests during ecological studies and conservation actions.