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Paley’s Watch found in cyanobacteria


Turns out it’s a bit more complicated than a Swiss watch. Emphasis added.

Science 31 October 2008:
Vol. 322. no. 5902, pp. 697 – 701
DOI: 10.1126/science.1150451

Structural Insights into a Circadian Oscillator
Carl Hirschie Johnson,1* Martin Egli,2 Phoebe L. Stewart3

An endogenous circadian system in cyanobacteria exerts pervasive control over cellular processes, including global gene expression. Indeed, the entire chromosome undergoes daily cycles of topological changes and compaction. The biochemical machinery underlying a circadian oscillator can be reconstituted in vitro with just three cyanobacterial proteins, KaiA, KaiB, and KaiC. These proteins interact to promote conformational changes and phosphorylation events that determine the phase of the in vitro oscillation. The high-resolution structures of these proteins suggest a ratcheting mechanism by which the KaiABC oscillator ticks unidirectionally. This posttranslational oscillator may interact with transcriptional and translational feedback loops to generate the emergent circadian behavior in vivo. The conjunction of structural, biophysical, and biochemical approaches to this system reveals molecular mechanisms of biological timekeeping.

Selected snips from the paper (subscription required for the full article):

Cogs and Gears: The Kai Proteins

The clockwork mechanism that controls these global rhythms of transcription, chromosomal topology, and cell division is composed of three essential proteins—KaiA, KaiB, and KaiC—which were identified in 1998 (15). Their three-dimensional structures, which became available in 2004 (16–21), are the only full-length structures of core circadian clock proteins that have been determined.

Therefore, the posttranslational cyanobacterial clockwork is composed of biochemical reactions such as phosphorylation, ATP hydrolysis, monomer exchange, and conformational changes among thousands of molecules per cell (~10,000 KaiC monomers per cell) (37), permitting robust oscillations of high precision and synchrony…..

The benefit of a clockwork that is imperturbable even when buffeted by the massive intracellular changes of cell division could have provided an evolutionary driving force for convergent circadian clock mechanisms among diverse organisms.

We now recognize KaiABC as a dynamically oscillating nanomachine that has evolved to precess unidirectionally and robustly. The challenges ahead are to delve deeper into the molecular nature of its temperature compensation, to examine the place of the PTO in the larger cellular program, and to discover if the clocks in our own cells have attributes that are similar to those of bacteria.

I agree with Borne. It is nice to be able to click on a link and check it out without losing the page you started from. I have noticed that Mrs O'Leary usually has a number of links in her posts, and they usually open in just that manner. feebish
Allanius, this is an interesting article, for several reasons, but the comparison of these time oscillators to Paley's watch is superficial when it comes to the central argument of ID, which is usually presented as the watchmaker argument. The genus of Oscillatoria (of cyanobacteria, or blue-green algae) was identified and named as such in early 1800's by Dr. Ehrenberg. People had wondered for a long time about the color of the Red Sea, and there were many speculations about the word "red", going back to the time of Herodotus and the Bible. Ehrenberg discovered that this was due to these small animalcules, which he named Oscillatoria. Now it is widely accepted that the Red Sea is named for an occasional bloom of the cyanobacteria, Trichodesmium erythraeum algae, which appear as red and pinkish blankets on the surface, and after they die, the sea turns reddish-brown. However, the blue-green algae don't have to have reddish pigment, the red color can also be caused by refraction, such as some Alp lakes turn blood-red by Oscillatoria rubescens because they have refractive pseudovacuoles. Another important point about cyanobacteria is that they play a crucial role in the "evolutionary" history — fossils of oxygen-producing cyanobacteria are from 2.8 billion years ago. They played and play a crucial role in photosynthesis, they supposedly killed off oxygen intolerant oganisms, and originated a biodiversity explosion of oxygen breathing organisms. The time aspect itself is also nothing new. The circadian cycle was initially discovered in 1700s by the plant leaf movement. (Carl Linne designed a floral clock based on plants.) The notion of biological time in animals dates back to 1860. In the wider context, the "time" aspect found in nature or in cyanobacteria has nothing to do with the "design" aspect of systems, other than incidentally. (Biological nano-oscillators are just one of many designs in nature.) Time is the crucial factor in nature, as Aristotle asserted and explained. Today we know that oscillations are everywhere in nature, from sub-atomic matter to biological time. rockyr
Excellent. Another slam-dunk from Dave. Maybe it's time to start talking about "Paley's revenge." The naturalists always claimed that basic science would vindicate their theories in time. Just the opposite is true. Basic science is demonstrating a fundamental resistance in being to nothingness. Note the engineering language--"oscillator"! It's interesting that the writers find it necessary to use such language to express themselves economically. An oscillator is a circuit. Its form precedes its function. The word "oscillator" indicates a fully functional sum of many parts. The sign becomes invested with transcendent significance grounded in the reality of nature itself. The long-standing critique offered by Nominalism loses its force. allanius
SCheesman said:
Perhaps we should be looking for “hour glass” and “water clock” biological structures in simpler organisms which must have provided the evolutionary stepping stones leading to this latest find?
lol That's hilarious! :D I love how the authors of the article just throw in that evolution must have done it with absolutely no proof to support that idea. It's not like they saw it evolve, or any other complex biological mechanism for that matter. This find is really interesting, and I like how DaveScote called it Paley's watch. Finding such a clock in organisms is just yet another example of an intelligent design within organisms. Keep in mind the only clocks known to exist were created via intelligence, and to find one within organisms is obviously a sign of intelligence. Not evolution like the authors claim. I mean, if they could point me to a mid-evolving clock maybe I'd chance my mind, but they can't just cite evolution as its source and expect me to believe it. Domoman
Would be nice if external links opened in a new window (tab). Allows one to stay on this page while still being to see the linked material. Denyse O. does her links like that now. Borne
The clockwork mechanism that controls these global rhythms of transcription, chromosomal topology, and cell division is composed of three essential proteins.
Sounds like an irreducably complex system, no? Do these proteins have any close relatives involved in any other functions from which they could have been co-opted? SCheesman
I find it amazing that "Adds by Google" came up with an advert for "luxury watches" as a sidebar with this article. Paley must be enjoying himself looking down at the current state of discovery. Perhaps we should be looking for "hour glass" and "water clock" biological structures in simpler organisms which must have provided the evolutionary stepping stones leading to this latest find? SCheesman

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