Kim Jin Seob, Sun Sean X
Biophys J. 2009 Apr 22;96(8):L47-9. doi: 10.1016/j.bpj.2009.02.010.
Bacterial cells exist in a wide variety of shapes. To understand the mechanism of bacterial shape maintenance, we investigate the morphology of Caulobacter crescentus, which is a Gram-negative bacterium that adopts a helical crescent shape. It is known that crescentin, an intermediate filament homolog of C. crescentus, is required for maintaining this asymmetrical cell shape. We employ a continuum model to understand the interaction between the bacterial cell wall and the crescentin bundle. The model allows us to examine different scenarios of attaching crescentin to the cell wall and compute the shape of the bacterium. Results show that if the sole influence of crescentin is mechanical, then the crescentin bundle is unrealistically rigid and must be attached to the cell wall directly. The model suggests that alternative roles for crescentin such as how it influences cell wall growth must be considered.
细菌细胞存在多种形状。为了解细菌形状维持的机制，我们研究了新月柄杆菌的形态，它是一种革兰氏阴性菌，呈螺旋状新月形。已知新月柄杆菌的中间丝同源物新月菌素是维持这种不对称细胞形状所必需的。我们采用连续介质模型来理解细菌细胞壁与新月菌素束之间的相互作用。该模型使我们能够研究将新月菌素附着到细胞壁的不同情况，并计算细菌的形状。结果表明，如果新月菌素的唯一作用是机械性的，那么新月菌素束将具有不切实际的刚性，并且必须直接附着到细胞壁上。该模型表明，必须考虑新月菌素的其他作用，例如它如何影响细胞壁生长。
