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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 […]

Stupid Evolution Quote of the Week: Cell Networks

A team of Chinese scientists analyzed protein interactions in yeast cells, and titled their paper in PNAS1 “The yeast cell-cycle network is robustly designed.”  They “demonstrated that the cell-cycle network is extremely stable and robust for its function,” and “able to survive perturbations.”  The beginning of the paper expresses the wonder the stimulated their research: […]

Cellular Cowboys: How the Cell Rounds Up Chromosomes Before Dividing

Two cancer researchers from UC San Diego describe mitosis (cell division) in the Mar. 4 issue of Nature.1  Pulling together the latest findings about this elaborate and important process, they begin by describing the puzzle that the cell needs to solve: At the beginning of mitosis, the process of cell division, chromosomes are organized randomly […]

DNA Is a Code Operated by Another Code

The discovery in the 1950s that DNA stored a coded language was amazing, but recently a new level of complexity has come to the awareness of biochemists.  Apparently, another code determines which DNA genes will be opened for expression and which should be suppressed.     The Feb. 14 issue of Science News1 describes the […]

Your Internal Motors Can Run Nanotech

In each cell in your body, and in that of every living thing, there exists a tiny motor named ATP synthase that Science News1 calls “the ultimate molecular machine.”  It converts electrical to chemical energy, writes Alexandra Goho, “with amazing efficiency.”  Now, Japanese have harnessed some of these motors (only 12 millionths of a millimeter […]

“Utmost Precision” Found in DNA Repair Enzyme

The cell has many helper enzymes that can repair DNA damage.  One such enzyme, named MutY, has been described in the Feb. 12 issue of Nature.1  Reviewer Tomas Lindahl sets the stage: “Damaged DNA must be removed with the utmost precision, as mistakes are costly.  The structure of a repair enzyme bound to its substrate […]
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