Abstract：
Recent structural and biophysical studies of O2-sensing FixL, NO-sensing soluble guanylate cyclase, and other biological heme-based sensing proteins have begun to reveal the details of their molecular mechanisms and shed light on how nature regulates important biological processes such as nitrogen fixation, blood pressure, neurotransmission, photosynthesis and circadian rhythm. The O2-sensing FixL protein from S. meliloti, the eukaryotic NO-sensing protein sGC, and the CO-sensing CooA protein from R. rubrum transmit their biological signals through gas-binding to the heme domain of these proteins, which inhibits or activates the regulatory, enzymatic domain. These proteins appear to propagate their signal by specific structural changes in the heme sensor domain initiated by the appropriate gas binding to the heme, which is then propagated through a coiled-coil linker or other domain to the regulatory, enzymatic domain that sends out the biological signal. The current understanding of the signal transduction mechanisms of O2-sensing FixL, NO-sensing sGC, CO-sensing CooA and other biological heme-based gas sensing proteins and their mechanistic themes are discussed, with recommendations for future work to further understand this rapidly growing area of biological heme-based gas sensors.
摘要：
O2传感FixL的最新结构和生物物理研究，NO敏感可溶性鸟苷酸环化酶，和其他基于血红素的生物传感蛋白已经开始揭示其分子机制的细节，并阐明自然如何调节重要的生物过程，如固氮，血压,神经传递,光合作用和昼夜节律。来自MelilotiS.的O2感应FixL蛋白，真核NO感应蛋白sGC，来自R.rubrum的CO感应CooA蛋白通过气体结合到这些蛋白的血红素域来传递它们的生物信号，抑制或激活监管，酶域。这些蛋白质似乎通过与血红素结合的适当气体引发的血红素传感器域的特定结构变化来传播其信号，然后通过卷曲螺旋接头或其他结构域传播到调节，发出生物信号的酶域。目前对O2传感FixL信号转导机制的理解，NO-sensingsGC,讨论了CO传感CooA和其他基于血红素的生物气体传感蛋白及其机理主题，建议未来的工作，以进一步了解这一快速增长的生物血红素基气体传感器领域。
