1.Введение

Про цианобактерии, состояние проблемы, железо, фур, цели и задачи.

2.Литобзор

2.1 Существование антисмысловых рнк у бактерий Evidence for a major role of antisense rnAs in cyanobacterial gene regulation.

Georg J, Voss B, Scholz I, Mitschke J, Wilde A, Hess WR.

Author information

• Faculty of Biology and Freiburg Initiative in Systems Biology, University of Freiburg, Freiburg 79104, Germany.

Abstract

Information on the numbers and functions of naturally occurring antisense RNAs (asRNAs) in eubacteria has thus far remained incomplete. Here, we screened the model cyanobacterium Synechocystis sp. PCC 6803 for asRNAs using four different methods. In the final data set, the number of known noncoding RNAs rose from 6 earlier identified to 60 and of asRNAs from 1 to 73 (28 were verified using at least three methods). Among these, there are many asRNAs to housekeeping, regulatory or metabolic genes, as well as to genes encoding electron transport proteins. Transferring cultures to high light, carbon-limited conditions or darkness influenced the expression levels of several asRNAs, suggesting their functional relevance. Examples include the asRNA to rpl1, which accumulates in a light-dependent manner and may be required for processing the L11 r-operon and the SyR7 noncoding RNA, which is antisense to the murF 5' UTR, possibly modulating murein biosynthesis. Extrapolated to the whole genome, approximately 10% of all genes in Synechocystis are influenced by asRNAs. Thus, chromosomally encoded asRNAs may have an important function in eubacterial regulatory networks.

Evidence for a major role of antisense RNAs in cyanobacterial gene regulation.

Georg J, Voss B, Scholz I, Mitschke J, Wilde A, Hess WR.

Author information

• Faculty of Biology and Freiburg Initiative in Systems Biology, University of Freiburg, Freiburg 79104, Germany.

Abstract

Information on the numbers and functions of naturally occurring antisense RNAs (asRNAs) in eubacteria has thus far remained incomplete. Here, we screened the model cyanobacterium Synechocystis sp. PCC 6803 for asRNAs using four different methods. In the final data set, the number of known noncoding RNAs rose from 6 earlier identified to 60 and of asRNAs from 1 to 73 (28 were verified using at least three methods). Among these, there are many asRNAs to housekeeping, regulatory or metabolic genes, as well as to genes encoding electron transport proteins. Transferring cultures to high light, carbon-limited conditions or darkness influenced the expression levels of several asRNAs, suggesting their functional relevance. Examples include the asRNA to rpl1, which accumulates in a light-dependent manner and may be required for processing the L11 r-operon and the SyR7 noncoding RNA, which is antisense to the murF 5' UTR, possibly modulating murein biosynthesis. Extrapolated to the whole genome, approximately 10% of all genes in Synechocystis are influenced by asRNAs. Thus, chromosomally encoded asRNAs may have an important function in eubacterial regulatory networks.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2758717/

2.2 Типы антисмысловых РНК

Бактериальные асРНК разнообразны, не имеют общих черт, кроме того факта, что считываются с противоположной цепи транскрипционной единицы. Тем не менее, они могут быть примерно классифицированы в зависимости от их расположения, как 5'-перекрывающиеся (расходящийся, голова к голове), 3'-перекрывающиеся (сходящийся, хвост к хвосту), или находящиеся внутри асРНК. Транскрипты от белок-кодирующих генов с длинными 5 'или 3' нетранслирующими областями, которые существенно перекрываются с мРНК, происходящих из других генов, представляют собой эффективный способ для сохранения регуляторных связей между генами. (анабена Identification of a furA cis antisense RNA in the cyanobacterium Anabaena sp. PCC 7120.[J Mol Biol. 2006] Hernández JA, Muro-Pastor AM, Flores E, Bes MT, Peleato ML, Fillat MF)

2.3 Механизм действия асРНК у бактерий

2.3.1. Изменение стабильности целевой РНК