A new perspective on homochiral DNA strands orientations and homochiral DNA structure
A new perspective on homochiral DNA strands orientations and homochiral DNA structure
A new perspective on DNA strands orientations and homochiral
structuring
The DNA strands might have formed homochiral DNA structure by positioning themselves in reversed(inverted) mirror images of each other. They should be copies of each other but not completely symmetrical. Both DNA strands are right handed and antiparallel, oriented in opposite directions but they may be located in reversed mirror image position of each other on DNA. For two right-handed structures to be localized in the homochiral position, they must be in a position that is the opposite of each other's mirror images. Leading strand inner side and it's inner side reversed mirror image position should be located to build in face to face position for homochiral DNA structuring.During the evolutionary process, in a prebiotic environment, a right-handed single-stranded DNA virus and its reversed mirror image, when paired, may form a primordial DNA.
Introduction
Since Pasteur pointed out chiral molecules, chirality, homochirality, and handedness have not been fully explained. It could be suggested that adding directionality to these concepts might be helpful for understanding them.A model based on "reversed mirror image opposite directional homochiral asymmetric polar structure of DNA" could explain many unknown things the formation of homochiral life. Homochirality is a property of living things and refers to the preference for only one of the right-handed or left-handed forms of the same molecule. DNA and RNA are R-handed, while all amino acids except glycine are L-handed In living organisms.Chilarity is the property of an object or molecule can't superpose to its mirror image .Chirality and handedness are used generally same meaning at the enantiomer level but there are small diferencies. Chirality is the geometric property of an object non-superimposable on its mirror image. Handedness tells orientation of chirality and we give a label those right- left or up-down to the chiral objects. However, considering chirality only at the enantiomer level might be misleading. At the macroscopic level, different and new perspectives on chirality and homochirality may be needed. Directionality can be very important in fully understanding homochiral, chiral, and handed structures. Chirality is not necessary for directionality, but a chiral molecule can be positioned in opposite directions. DNA strands are R-handed but they are located in opposite directional positions.Left-handed amino acids may be also arranged in reversed mirror images on the right and left sides of the body to form a homochiral structure. (Figure2,4) Handedness and chirality cannot be changeble but directions can be change acording to the position. According to an axis passing vertically through the exact center of the human body, the right and left sides of the body and the dual organs within them must be homochiral. The brain hemispheres, eyes, ears, lungs, kidneys, testes, ovaries, arms, legs, and hands are homochiral. These are mirror images of each other and oppositely oriented homochiral structures that are not perfectly symmetrical. Our planet's northern and southern hemispheres can meet at the equator, forming a chiral structure that is oppositely oriented and asymmetrical. Venus-Earth, Jupiter-Saturn, Uranus-Neptune are similar neighboring planets, but they are not perfectly symmetrical, and the distance between them is close to zero on a cosmic scale, which could make them chiral. Andromeda and the Milky Way are neighboring spiral galaxies moving towards each other in opposite directions; they may be chiral. Chirality may also be universal for oppositely oriented asymmetric binary structures
Figure2.Details. We cannot make right glove without altering its structure as a left glove but we can change its directional position. If we hold our right hand with our palmar side open, the thumb of the right hand points to the right direction and its reversed mirror image position points left direction. If the hand palms are held downwards, the thumb of the right hand points to the left direction and left hand thumb points right direction "Handedness,chirality and homochirality cannot be changeable but directionality can ce changeable.
"Asymmetric duality with opposite directional,” may be observed in almost everything, from subatomic particles to possible twin universes" Figure1.Details. We cannot make right glove without altering its structure as a left glove but we can change its directional position. If we hold our right hand with our palmar side open, the thumb of the right hand points to the right direction and its reversed mirror image position points left direction. If the hand palms are held downwards, the thumb of the right hand points to the left direction and left hand thumb points right direction "Handedness,chirality and homochirality cannot be changeable , but directionality can be changeable”
In homochiral living structures,
"asymmetric duality along with opposite directionality and polarity"
must be a fundamental characteristic of life. DNA may be the most important
molecule possessing all these characteristics in its structure. DNA strands
are antiparallel,oposite orientationted
and R-handed structure, they must be homochiral.Leading and lagging strands
should be arranged in the opposite direction of each other's mirror images.The
lagging strand may be structured as an inverted mirror image of the leading
strand. In other words, DNA strands may be located in reversed mirror
image position of each other. This type of model may have been developed
during evolution and enabled the transition to multicellular organisms. Figure
3). All processes in replication, transcription, and protein synthesis appear
to mimic the homochiral structure of DNA by molecular mechanism.
This study tries to explain how R-handed DNA
strands can be in an inverted(reversed) mirror image position within homochiral
DNA. Additionally, the possible differential
localization of homochiral L-handled amino acids in the right and left sides of
the body is briefly mentioned.
A new perspective that may add to explain the
DNA structure model.
Most
DNA double helices are right-handed; that is, if you were to hold your right
hand out, with your thumb pointed up and your fingers curled around your thumb,
your thumb would represent the axis of the helix and your fingers would
represent the sugar-phosphate backbone. Only one type of DNA, called Z-DNA, is
left-handed.The DNA double helix is anti-parallel, which means that the 5' end
of one strand is paired with the 3' end of its complementary strand (and vice
versa). Nucleotides are linked to each other by their phosphate groups, which
bind the 3' end of one sugar to the 5' end of the next sugar.[1]Any given DNA strand is a polymer of
nucleotides, which has a polarity, specified by the chemical nature of the
groups marking the first and the last nucleotide in the polymer chain. The
beginning of a DNA strand is called the 5′-end, since it terminates
with the phosphate group of the C′5 atom of the deoxyribose sugar of the
first nucleotide, while the opposite extremity is called the 3′-end, since it
terminates with the hydroxyl group of the C′3 atom of the deoxyribose sugar of
the last nucleotide.[2] Each DNA
strand has polarity and it also might be necessary for DNA functions together
with opposite directional antiparallel
homochiral DNA structuring. DNA strands
might be located in reversed(inverted)mirror image of each others position and they have
polarity and opposite directionaity.
Now,the the question is why it might be necessary for
DNA strands to be in reversed mirror image positions.The short answer is this:
Two R-handed molecules,theirs inner surfaces face
to face to each other in opposite directional position can only be localized in
the reversed mirror image of each
other's . Similarly, the R-handed DNA
strands are located in opposite direction antiparallel, that is reversed mirror
image of each other and it may be necessary for homochiral structure of DNA.
We can easily put two right gloves on top of
each other symmetrically but it is not possible to bring the inner surfaces of
them face to face position symmetrically and their position is mirror image of
each others. When we look our right hand in a mirror, we see
it as if it was your left hand, but what we see is your right hand. We
can easily place the palms of our right and left hands opposite to each other
because they have opposite directionality. (Actually, they are not perfectly symmetrical.)
For the face-to-face position, the opposite
directions are required.How can we positioned the inner surfaces (palms) of two
right gloves in opposite directions, antiparallel and face to face. When we rotate one of the glove 180 degrees counterclockwise, the inner
surfaces of the gloves face to each other,they are located in
anti-parellel opposite directional and
reversed mirror image position of each other and this is similar to the
position of DNA strands. (Figure 2.)
Paired bases are attached to the inner
side(face) of the sugar-phosphate backbone in the DNA double helix. Therefore, the correct positioning of the inner
surfaces of the DNA strands facing each other is crucial and essential.Both DNA
strands are right-handed, but one is oriented to the right and the other to the
left or up-down in opposite directions (5'-3' and 3'-5'). This arrangement
pattern should only be possible if the two right-handed strands are arranged in
opposite mirror-image positions. In other words, the DNA strands must be
localized in reversed mirror image positions of each others for homochiral DNA
structure.
DNA can have opposite directional and polar
homochiral dual structuring, but they are not perfectly symmetrical. Both strands are R-handed but directions are
localizied in oppositely. If one of the strand is R-handed-R-directional the
other one must be R-handed-Left-directional due to its reverse mirror image
position. Both R-handed strands can only form a helical homochiral structure
with this type of arrangement pattern. Reversed mirror image positions of each
other R-handed DNA strands might be essential for homochiral structuring in all
the living things. Evolution has managed
to localize both R-handed strands inner faces to face each other by reversed
mirror image positions and developing eukaryotic organisms. All molecular processes in replication,
transcription, and protein synthesis appear to mimic the homochiral structure
of DNA.
Viruses are notorious for rapidly exchanging
genetic information between close relatives and with the host cells they
infect. This exchange has profound effects on the nature and rapidity of virus
and host evolution. Recombination between dsDNA viruses is common, as is
genetic exchange between dsDNA viruses or retroviruses and host genomes.
Recombination between RNA virus genomes is also well known. However, there is now growing evidence for both
RNA and ssDNA viruses recombining with host dsDNA genomes and, more
surprisingly, RNA virus genes recombining with ssDNA virus genomes. Mechanisms
are still unclear, but this deep recombination greatly expands the breadth of
virus evolution and confounds virus taxon [4]
During the evolutionary process, R-elli dsDNA,
ssDNA and RNA virusses may have contributed to the formation of primordial DNA.
The molecular recognition properties of viruses, which can utilize and infect
the genomes of all living things, may be due to their contribution to the
structure of primordial DNA strands in the early stages of evolution. The
possible formation of primordial DNA is attempted to be explained by
considering its potential similarity to DNA structure. Figure [3]
Figure 3. (Modified from Quizlet.Morphology of
the virus) In the evolutionary process, posible formation of primordial DNA and
the transition to multicellular organisms may be tried to explain by this
figure. Single strand DNA virus and it's reversed mirror image position might be combined in face to face position in the prebiotic
soup.
Given that RNA virus genes are known to
recombine with ssDNA virus genomes, it is possible that RNA viruses have
contributed to primordial DNA formation in some way. Evolution has managed to
localize both R-handed and R- directional strands inner faces to face each
other by reversed mirror image positions and developing eukaryotic organisms.
Figure 4. Figüre a,from Template:PD-USGov-Unincorporated/doc. (unchanged)
Figüre b. The possible localization of left-handed amino acids in the right and left sides of the body is shown in this figure. Left hand palmar side and its inverted mirror image position may be similar to the location of enantiomers. L-handed aminoacidos might be located in reversed mirror image position of each other in the right and left parts of the body. Left hand palmar side and reversed mirror image position of the left hand position may be also valid for aminoacides in the right and left part of the body. This model or localization may be necessary for mirror image homochiral bilateral body structuring, like right and left hands in opposite directions
Discussion
Directionality might be considered in
conjunction with chirality, homochirality, and handedness.Reversed mirror-image
arrangement of the strands may be necessary understanding the all the
homochiral mechanisms in living things. Opposite directional and polar homochiral dual
asymmetric structuring may be necessary to occuring multicelluler eukaryotic
living things.A single body structure is formed when the right and left parts
of the body meet precisely at the midline.For the formation of two opposing bi-
directional body part building , L-handed aminoacids might
be located in opposite directional positions of each other on the right
and left sides of the body.Figure 4.
As the Human Genome Project (HGP) progressed,
there were such major surprises as the observation that only 1.2% of the
sequence was represented in protein-coding genes, revealing ignorance or
uncertainties about the roles of the rest of the DNA.[3] The length of DNA in a
cell is about 2 meters. Various studies report that there are approximately 30-35
trillion cells on average in both male and female.In a structure as long as DNA
trillions meters, not all DNA strands can exist in reversed mirror-image
positions or anti-parelel and opposite directional perfectly.This could be one
of the reason why only a small portion
of the DNA is used. Reverse mirror-image arrangements perfectly may occur in
gene regions, which make up approximately 1.2% of DNA.
It may be also possible DNA and genes in the
cells of the right and left sides of the body located in reversed mirror images
positions of each other.It may be build to provide for the mirror image
homochiral structuring of the right and left body parts and organs in humans
and other living beings.
References
1.Leslie A.Pray,ph.D.Discovery of DNA structure
and Function:Watson and Crick
2008 Nature education 1(1):100
2.Giovanni Maga. DNA
Replication. Module Biomedical Sciences,2017
https://doi.org/10.1016/B978-0-12-374984-0.00431-9
3. Omenn GS
(2021). "Reflections
on the HUPO Human Proteome Project, the Flagship Project of the Human Proteome
Organization, at 10 Years". Molecular
& Cellular Proteomics. 20 100062. doi:10.1016/j.mcpro.2021.100062. PMC 8058560. PMID 33640492
4. Kenneth
M Stedman. Deep Recombination: RNA and ssDNA Virus Genes in DNA Virus and Host Genomes.
2015 Nov;2(1):203-17. Epub 2015 Sep 2. DOI: 10.1146/annurev-virology-100114-055127
Etiketler: A new perspective on homochiral DNA strands orientations and homochiral DNA structure.
Dr. Engin Sayın tarafından gönderildi @ Ocak 07, 2026
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