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Cell Nucleus Complexity Baffles Evolutionists

In her inimitable way, Science reporter Elizabeth Pennisi has once again portrayed a scientific controversy undergoing active ferment.  This time it’s about the evolutionary origin of cell nuclei, which she terms “specialized, DNA-filled command centers.”1  At the conclusion, she gives prominence to a “provocative, but circumstantial and controversial” suggestion that viruses taught cells how to […]

Gymnastic Enzyme Acts Like Logic Gate

An enzyme named vinculin undergoes “drastic” conformational changes, reports William A. Weis in the July 29 issue of Nature.1  Vinculin, with over a thousand amino acid links, is important at membrane junctions for transporting materials in and out of the cell.  It helps cellular “glue” exit the membrane so that neighboring cells can adhere to […]

Spaghetti in a Basketball: How the Cell Packs DNA for Controlled Access

The beginning sentence of an article in Current Biology1 can’t help but grab your attention: Imagine trying to stuff about 10,000 miles of spaghetti inside a basketball.  Then, if that was not difficult enough, attempt to find a unique one inch segment of pasta from the middle of this mess, or try to duplicate, untangle […]

How Cells Build Hard Parts

You have rocks in your head, and it’s a good thing, or you would die of starvation and imbalance.  Living things have need of inorganic structures for various functions.  Can you name the mineral structures in your body?  The answer is: bone, dentin, enamel and otoliths.  The last three are specific to your head.  Dentin […]

Engineers Envy Diatoms’ Glass-Sculpturing Prowess

What is it?  An ornate crown?  A crystal serving dish cover?  A work of art?  The photo on the cover of the July 17 Science News, labeled “silicon jewels,” is a microphotograph of a diatom, a one-celled organism that lives in the sea and builds itself a glass house too small to see with the […]

Cell Cargo Speeds On Bidirectional Highways

As reported here numerous times (e.g., 06/14/2004, 12/04/2003, 04/14/2003, 03/28/2003, 02/25/2003, 12/17/2002, 09/26/2002, 03/26/2002, 02/01/2002, 12/06/2001, 08/17/2001, 06/19/2001, 02/21/2001), cells have an elaborate interstate highway system with molecular trucks hauling cargo back and forth.  Scientists have known that the cellular highways have polarities labeled plus and minus, and that molecular motors typically go one way.  […]

Archaea Have Their Own Proofreading Mechanism

A team of Yale biochemists investigated a proofreading mechanism in one-celled organisms from the domain Archaea and found it different, but just as effective, as its counterpart in domains Bacteria and Eukarya (the latter including all plants and humans).  Their work was published online in PNAS July 6.1     The particular instance involved the […]

Cell Technology Celebrated

Humans are just beginning to imitate the manufacturing techniques cells use all the time, right under our noses.  A book just came out about the subject, entitled Bionanotechnology: Lessons from Nature by David S. Goodsell.  It’s hard to tell if Christof M. Niemeyer was more impressed with the book or with the living machines themselves, […]

Biochemists Mutate Protein, Make a Catalyst

“Enzymes are among the most proficient catalysts known,” wrote three Duke University scientists, “and they catalyze a wide variety of reactions in aqueous solutions under ambient conditions with exquisite selectivity and stereospecificity.”  The team set out to rationally design their own enzyme.  Their work is reported in the June 25 issue of Science.1  Building on […]

How Molecular Trucks Build Your Sensors

In the film Unlocking the Mystery of Life, biochemist Michael Behe, describing the intricacies of cells as we know them today, claimed that there are “little molecular trucks that carry supplies from one end of the cell to the other.”  If that seems an overstatement, you should look at the illustration in Cell June 11 […]

DNA Folds With Molecular Velcro

Many have heard how the inventor of Velcro got the idea from plant seeds that stick to clothing, but now Carlos Bustamente and team of Howard Hughes Medical Institute have found a velcro-like principle operating at a scale millions of times smaller.  Small proteins called condensins are involved in the elaborate folding that DNA undergoes […]

Cell Requires Two Keys to Let Cargo Pass

For high-security environments, guards sometimes require two independent authentication methods.  Before humans came up with this trick, the cells in their bodies were already using it.  Itoh and Camilli explain in the May 13 issue of Nature:1 Our cells contain a series of distinct compartments that do different jobs and have different properties.  The membranes […]

Botulinum Toxin Deactivated by One Slight Change

A researcher at Brookhaven National Laboratory mutated a botulinum enzyme by just one amino acid, and abolished its toxicity.  The mutation, a change from a glutamate to a glutamine at one position, increased the distance from a zinc atom to a water molecule by 0.6 angstrom, less than one tenth of a billionth of a […]

Virus: Like DNA in a Hard Plastic Shell

A European team of biophysicists studied the mechanical properties of a virus and found the shell, made of protein, to act like hard plastic.  Writing in PNAS,1 they described the coat of a bacteriophage they studied: The protective proteinaceous shells (capsids) of viruses are striking examples of biological materials engineering.  These highly regular, self-assembled, nanometer-sized […]

Minimal Cell Modeled in Computer

“The basic design rules relating the regulation of cellular function to genomic structure is of broad interest,” begin three Cornell microbiologists writing in PNAS,1 and so they have turned their attention to the smallest theoretical living cell: A �minimal cell� is a hypothetical cell possessing the minimum functions required for sustained growth and reproduction in […]
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