Paper
7 September 2010 Cyanobacteria gene and protein sequences in diurnal oscillation metabolic processes
George Tremberger Jr., T. Holden, E. Cheung, S. Dehipawala, N. Gadura, U. Golebiewska, K. Valentin, M. Smulczeski, W. Satizabal, P. Schneider, D. Lieberman, T. Cheung
Author Affiliations +
Abstract
Daytime photosynthesis and nighttime nitrogen fixation metabolic processes have been reported in the bacterium, Cyanothece 51142. The organism's auto-fluorescence with 532 nm excitation would place cyanobacteria at the forefront in the remote sensing of microbial activity in astrobiology. The sensitivity of nitrogenase to oxygen was studied in terms of sequence nucleotide fluctuation. A nucleotide sequence fractal dimension can be calculated from a numerical series consisting of the atomic numbers of each nucleotide. The fractal dimension and Shannon entropy form a two-dimensional measure that is useful in assessing evolutionary pressures. The studied sequences include nitrogenase iron protein NifH, nitrogenase molybdenum-iron protein alpha chain NifD and beta chain NifK. The photosynthesis-lacking UCYN-A cyanobacterium as reported recently in the journal, Nature, was observed to have the lowest entropy with relatively high fractal dimension values in the studied NifH, NifD and NifH sequences. The fractal dimension of NifH sequences correlates with the NifD sequence values with an R-square of 0.91 (N = 8). The Shannon mononucleotide entropy of NifD sequences correlates with the NifK sequence values with an R-square value of 0.92 (N = 8). The observed strong correlation suggests the presence of gradual evolutionary pressure among the studied cyanobacteria, and throws light on the reported paradox in evolution for the case of UCYN-A. The results show that diurnal oscillation metabolic processes in cyanobacteria (including the photosynthesis-deficient case) are not associated with extraordinary evolutionary pressures and thus are processes consistent with putative astrobiological organisms.
© (2010) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
George Tremberger Jr., T. Holden, E. Cheung, S. Dehipawala, N. Gadura, U. Golebiewska, K. Valentin, M. Smulczeski, W. Satizabal, P. Schneider, D. Lieberman, and T. Cheung "Cyanobacteria gene and protein sequences in diurnal oscillation metabolic processes", Proc. SPIE 7819, Instruments, Methods, and Missions for Astrobiology XIII, 78190U (7 September 2010); https://doi.org/10.1117/12.860093
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Fractal analysis

Proteins

Biology

Iron

Organisms

Photosynthesis

Image information entropy

Back to Top