UH researchers find myoglobin-like proteins in ancient microorganisms A University of Hawaii research team has discovered a new class of myoglobin-like proteins in ancient microorganisms. In animals, myoglobin (found in muscle) and its close relative hemoglobin (the main protein in the red blood cell) play an essential role in oxygen transport and storage. The newly identified proteins may be the evolutionary ancestors of proteins involved in oxygen sensing as well as transport and storage. The findings, which appear in the Feb. 3 issue of the British journal Nature, add another piece to the puzzle of when and how life arose and evolved on earth.
The research team that made this discovery is headed by Maqsudul Alam, associate professor of microbiology, and Randy Larsen, associate professor of chemistry, both of the University of Hawaii at Manoa's College of Natural Sciences. Their team cloned the genes expressing these proteins, which were then purified and characterized. The newly discovered proteins from the ancient microorganism Halobacterium salinarum and the more widely known bacterium Bacillus subtilis share similar properties. These proteins help sense oxygen, allowing the organism to find a more favorable oxygen environment.
"These proteins may help to understand how sensory systems evolved in higher organisms," said Alam, lead author on the Nature paper. Cells must continually sense their changing environment, interpret the sensation and adapt to new surroundings. In multicellular organisms (including humans), sensing is accomplished using specialized sense organs as well as complex mechanisms to communicate this information to other parts of the organism.
"The presence of oxygen in the earth's atmosphere some 1 to 2 billion years ago was both a blessing and a curse," Alam says. Oxygen is an energy-rich molecule that can provide an energy source for cellular function. However, oxygen can also be highly toxic. The challenge for bacteri
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