Most proteins adopt an approximate structural symmetry. However, they have no symmetry detectable in their sequences and it is unclear for most of these proteins whether their structural symmetry originates from dupli...Most proteins adopt an approximate structural symmetry. However, they have no symmetry detectable in their sequences and it is unclear for most of these proteins whether their structural symmetry originates from duplication. As one of the six popular folds (super-folds) possessing an approximate structural symmetry, the triosephosphate isomerase barrel (TIM-barrel) domain has been widely studied. Using modified recurrent quantification analysis of primary sequences, we identified the same 2-, 3-, and 4-fold symmetry pattern as their tertiary structures. This result indicates that the symmetry in tertiary structure is coded by symmetry in the primary sequence and that the TIM-barrel adopts a 2-, 3-, or 4-fold repeat pattern during evolution. This discovery will be useful for understanding the evolutionary mechanisms of this protein family and the symmetry pattern that may be a clue into the ancient origin of duplication of half-barrels or the β a unit.展开更多
According to the method for predicting strong earthquakes using seismicity patterns,this paper summarizes the seismicity anomalies, generally called anomalous seismicity patterns,as the basis for prediction based on s...According to the method for predicting strong earthquakes using seismicity patterns,this paper summarizes the seismicity anomalies, generally called anomalous seismicity patterns,as the basis for prediction based on some historical data in the Sichuan-Yunnan seismic zone. Using our results,it can be confirmed that these anomaly patterns,which reflect the features of the late stage of strong earthquake preparation process and stress release in the main shock rupture zone,did exist before many earthquake cases. This paper also introduced the characteristics of seismic repeatability and its validation result,and discussed the mechanism of repeatability,which will have an application value for strong earthquake tendency prediction.展开更多
文摘Most proteins adopt an approximate structural symmetry. However, they have no symmetry detectable in their sequences and it is unclear for most of these proteins whether their structural symmetry originates from duplication. As one of the six popular folds (super-folds) possessing an approximate structural symmetry, the triosephosphate isomerase barrel (TIM-barrel) domain has been widely studied. Using modified recurrent quantification analysis of primary sequences, we identified the same 2-, 3-, and 4-fold symmetry pattern as their tertiary structures. This result indicates that the symmetry in tertiary structure is coded by symmetry in the primary sequence and that the TIM-barrel adopts a 2-, 3-, or 4-fold repeat pattern during evolution. This discovery will be useful for understanding the evolutionary mechanisms of this protein family and the symmetry pattern that may be a clue into the ancient origin of duplication of half-barrels or the β a unit.
文摘According to the method for predicting strong earthquakes using seismicity patterns,this paper summarizes the seismicity anomalies, generally called anomalous seismicity patterns,as the basis for prediction based on some historical data in the Sichuan-Yunnan seismic zone. Using our results,it can be confirmed that these anomaly patterns,which reflect the features of the late stage of strong earthquake preparation process and stress release in the main shock rupture zone,did exist before many earthquake cases. This paper also introduced the characteristics of seismic repeatability and its validation result,and discussed the mechanism of repeatability,which will have an application value for strong earthquake tendency prediction.
