It is shown that information transmission inside a cell can occur by means of mechanical waves transmitted through DNA. The propagation of the waves is strongly dependent on the shape of the DNA thus proteins that change the shape of DNA can alter signal transmission. The overall effect is a method of signal processing by DNA binding proteins that creates a "cellular communications network".
The propagation of small amplitude disturbances through DNA is treated according to the mechanical theory of elastic rods. According to the theory four types of mechanical waves affecting extension(compression), twist, bend or shear can propagate through DNA. Each type of wave has unique characteristic properties. Disturbances affecting all wave types can propagate independently of each other. Using a linear approximation to the theory of motion of elastic rods, the dispersion of these waves is investigated. The phase velocities of the waves lies in the range 5-8 angstroms/ps using constants suitable for a description of DNA. The dispersion of all wave types of arbitrary wave length is investigated for a straight, twisted rod.
Based on these findings, we propose all-atom numerical simulations of DNA to investigate the propagation of these waves as an alternative measure of the wave velocity and dispersion analysis.
Circumferential gap propagation in an anisotropic elastic bacterial sacculus
我们已经模拟了应力集中在各向异性的弹性片，对应于细菌细胞的肽聚糖球囊的小间隙周围，在负荷下对应于棒形细菌的膨压的影响。我们发现，在正常条件下，应力集中是不足以机械破裂细菌，即使是长达一微米的差距。然后，我们探索了由Arthur L Koch假设的应激依赖性smart-autolysins的作用[Advances in Microbial Physiology 24，301（1983）; Research in Microbiology 141，529（1990）]。我们表明，PG球囊的测量各向异性弹性可以导致球囊中小间隙的稳定周向传播。这与最近在杆状细菌中观察到PG相关MreB斑块的周向传播一致。我们还发现了一个周向和轴向间隙传播，这同意在细胞骨架突变体的B。枯草杆菌。我们的结论是，弹性各向异性的细菌球囊，其特征在于实验，可能是相关的维持杆状细菌的生长。
