The DABA-DC-AT RNA motif is a conserved
RNA
Ribonucleic acid (RNA) is a polymeric molecule that is essential for most biological functions, either by performing the function itself (non-coding RNA) or by forming a template for the production of proteins (messenger RNA). RNA and deoxyrib ...
structure that was
discovered by bioinformatics.
DABA-DC-AT motifs are found in
Gammaproteobacteria
''Gammaproteobacteria'' is a class of bacteria in the phylum ''Pseudomonadota'' (synonym ''Proteobacteria''). It contains about 250 genera, which makes it the most genus-rich taxon of the Prokaryotes. Several medically, ecologically, and scienti ...
, but overwhelmingly in the order
Vibrionales.
DABA-DC-AT motif RNAs likely function as
cis-regulatory element
''Cis''-regulatory elements (CREs) or ''cis''-regulatory modules (CRMs) are regions of non-coding DNA which regulate the transcription of neighboring genes. CREs are vital components of genetic regulatory networks, which in turn control morpho ...
s, in view of their positions upstream of protein-coding
gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...
s. These genes include those encoding
L-2,4-diaminobutyrate decarboxylase (DABA-DC),
L-2,4-diaminobutyrate aminotransferase (DABA-AT) and
carboxynorspermidine decarboxylase. ''
Vibrio cholerae
''Vibrio cholerae'' is a species of Gram-negative bacteria, Gram-negative, Facultative anaerobic organism, facultative anaerobe and Vibrio, comma-shaped bacteria. The bacteria naturally live in Brackish water, brackish or saltwater where they att ...
'', one of the organisms with a DABA-DC-AT RNA, is known to synthesize ''nor''-
spermidine
Spermidine is a polyamine compound () found in ribosomes and living tissues and having various metabolic functions within organisms.
Function
Spermidine is an Aliphatic compound, aliphatic polyamine. Spermidine synthase (SPDS) catalyzes its form ...
, and it is possible that the regulated genes are part of a pathway to synthesize this metabolite.
Structurally, the motif consists of four
hairpins, of which only one is well supported by
covariation
In probability theory and statistics, covariance is a measure of the joint variability of two random variables.
The sign of the covariance, therefore, shows the tendency in the linear relationship between the variables. If greater values of one ...
evidence. Thus, although there is strong evidence that the motif corresponds to a biological RNA, the precise structure remains unclear.
References
{{reflist
Non-coding RNA