Ionic Effects on Viral DNA Packaging and Portal Motor Function in Bacteriophage

Introduction

Viruses infect cells such as bacteria because they cannot multiply themselves. In so doing, using molecules and it's unfortunate host enzymes to replicate its genome and to build its viral shells, which are very similar to a spacecraft but in this case only DNA or RNA carrying the sole purpose of repeating another victim cycle. One of the key processes throughout viral infection is the packaging of the genetic material within those capsules. This process is not as simple as paint us in the books, we see that molecules of DNA (or RNA) newly copied, are drifting in the cytoplasm, and as if by magic, proteins begin to wrap to form new viruses are then released by cell explosion. To explain this in a simple way, today board the case of adenovirus, herpes viruses, pox viruses and bacteriophages with tail. All of these have a genetic material comprising a double stranded DNA (Cann, 2000, pp. 79 - 85).

The main problem with the packaging is the length of the DNA. To give you an idea of how difficult it is, imagine you are eating some tasty spaghetti, but this is one very peculiar, is made by a single noodle three meters long and half a centimeter thick. Now, take the spaghetti at one end, put it to his mouth and began to suck up finish (NOTE: do not bite it or drag it or break it). As the noodle is entering the oral cavity, the speed at which it does decreases, because the mouth is increasingly crowded, and the internal pressure increases. The process is similar viruses: the mouth is the viral capsule, the noodle is DNA and the lips will suck the noodle packaging motor protein ATP-dependent or translocator.

Background

The pressure inside the capsule increases and the viral packaging speed decreases as the genetic material is entering. This is because phi29 phage DNA (protagonist video), measuring 6.6 micrometers (0.0066 mm) in length, to enter into a cavity of only 0.00005 cubic microns, causing the pressure inside the capsule reaches the value exorbitant of 60 atmospheres (the same pressure that supports a submerged submarine at 600 meters deep). Then translocase must generate a force high enough to introduce the DNA against that pressure. Most studies the physicochemical, biochemical and thermodynamic elementary molecules for life, have been performed in chemical solutions with concentrations ranging from the order of micromolar until nanomoles and picomoles. Although it sounds like a very small amount at a picomole can find more than 600 billion molecules. In other words, most of the biochemical properties known to date are no more than the average of the global behavior of a large number of bio-molecules (David, 1996, pp. 213 - 225). However, many times does not represent what really happens if we analyze them one by one.

In the late 1980's, a group of researchers from the University of New Mexico, including Peruvian biologist Carlos Bustamante, developed a technique to ...