Horizontal transfer - imperative mission of acellular life forms, .

is a kingdom of life covering satellites, plasmids, transposable elements, viroids and viruses, all outside the conventional tree of life but satisfying most life definitions. This review focuses on some aspects of , their "genomes" and life styles, the dominance of transposable elements and their evolutionary influence on other life forms in order to vindicate the as a life kingdom no more polyphyletic than other kingdoms and its members no more parasitic than other life forms.

Transcription factors operate TATA switches via rotational remodeling of local columnar chromatin structure.

Our earlier study on the nucleosomes containing TBP binding sites (TATA boxes) indicated that generally the same sequence, which harbors the TATA box, encodes simultaneously an alternative rotational setting of the box, so that the TATA element is either exposed (position "minor groove out") or hidden in position "minor groove in". The sequence elements (dinucleotides) residing on the inner surface of DNA in contact with histone octamers are identified by calculating YR tracks in the promoter regions of the genes - periodically reappearing YR elements, at distances of 10-11 bases from one another. Non-YR elements of the YR tracks are also verified by nucleosome mapping procedure based on alternation of runs of purines with runs of pyrimidines.

Acytota - associated kingdom of neglected life.

There is a huge variety of RNA- and DNA-containing entities that multiply within and propagate between cells across all kingdoms of life, having no cells of their own. Apart from cellular organisms, these entities (viroids, plasmids, mobile elements and viruses among others) are the only ones with distinct genetic identities but which are not included in any traditional tree of life. We suggest to introduce or, rather, revive the distinct category of acellular organisms, Acytota, as an additional, undeservedly ignored full-fledged kingdom of life.

Sequence structure of Lowary/Widom clones forming strong nucleosomes.

Lowary and Widom selected from random sequences those which form exceptionally stable nucleosomes, including clone 601, the current champion of strong nucleosome (SN) sequences. This unique sequence database (LW sequences) carries sequence elements which confer stability on the nucleosomes formed on the sequences, and, thus, may serve as source of information on the structure of "ideal" or close to ideal nucleosome DNA sequence. An important clue is also provided by crystallographic study of Vasudevan and coauthors on clone 601 nucleosomes.

Nucleosome repeat lengths and columnar chromatin structure.

Thorough quantitative study of nucleosome repeat length (NRL) distributions, conducted in 1992 by J. Widom, resulted in a striking observation that the linker lengths between the nucleosomes are quantized. Comparison of the NRL average values with the MNase cut distances predicted from the hypothetical columnar structure of chromatin (this work) shows a close correspondence between the two.