Uptake signal sequences (USS) are short DNA sequences preferentially taken up by competent

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...

of the family

Pasteurellaceae The Pasteurellaceae comprise a large family of Gram-negative bacteria. Most members live as commensals on mucosal surfaces of birds and mammals, especially in the upper respiratory tract. Pasteurellaceae are typically rod-shaped, and are a notabl ...

(''e.g.'', ''

Haemophilus influenzae ''Haemophilus influenzae'' (formerly called Pfeiffer's bacillus or ''Bacillus influenzae'') is a Gram-negative, non-motile, coccobacillary, facultatively anaerobic, capnophilic pathogenic bacterium of the family Pasteurellaceae. The bacteria ...

''). Similar sequences, called DNA uptake sequences (DUS), are found in species of the family

Neisseriaceae The Neisseriaceae are a family of Pseudomonadota, within the ''Neisseriales'' order. While many organisms in the family are mammalian commensals or part of the normal flora, the genus ''Neisseria'' includes two important human pathogens, specifi ...

(including ''

Neisseria meningitidis ''Neisseria meningitidis'', often referred to as meningococcus, is a Gram-negative bacterium that can cause meningitis and other forms of meningococcal disease such as meningococcemia, a life-threatening sepsis. The bacterium is referred to as a ...

'' and ''

Neisseria gonorrhoeae ''Neisseria gonorrhoeae'', also known as ''gonococcus'' (singular), or ''gonococci'' (plural), is a species of Gram-negative diplococci bacteria isolated by Albert Ludwig Sigesmund Neisser, Albert Neisser in 1879. It causes the sexually transmit ...

'').

''Neisseria meningitidis''

Genetic transformation In molecular biology and genetics, transformation is the genetic alteration of a cell resulting from the direct uptake and incorporation of exogenous genetic material from its surroundings through the cell membrane(s). For transformation to ta ...

is the process by which a recipient bacterial cell takes up naked DNA from its environment and integrates this DNA into the recipient's genome by recombination. In ''

N. meningitidis ''Neisseria meningitidis'', often referred to as meningococcus, is a Gram-negative bacterium that can cause meningitis and other forms of meningococcal disease such as meningococcemia, a life-threatening sepsis. The bacterium is referred to as a ...

'', DNA transformation requires the presence of short DUS (10-12 mers residing in coding and intergenic regions) of the donor DNA. Specific recognition of DUSs is mediated by a type IV

pilin Pilin refers to a class of fibrous proteins that are found in pilus structures in bacteria. These structures can be used for the exchange of genetic material, or as a cell adhesion mechanism. Although not all bacteria have pili or fimbriae, bact ...

. Davidsen et al. reported that in ''N. meningitidis'' DUSs occur at a significantly higher density in genes involved in

DNA repair DNA repair is a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome. In human cells, both normal metabolic activities and environmental factors such as radiation can cause DNA dam ...

and recombination (as well as in restriction-modification and replication) than in other annotated gene groups. These authors proposed that the over-representation of DUS in DNA repair and recombination genes may reflect the benefit of maintaining the integrity of the DNA repair and recombination machinery by preferentially taking up genome maintenance genes that could replace their damaged counterparts in the recipient cell's genome. Uptake of such genes could provide a mechanism for facilitating recovery from DNA damage after

genotoxic Genotoxicity is the property of chemical agents that damage the genetic information within a cell causing mutations, which may lead to cancer. While genotoxicity is often confused with Mutagen, mutagenicity, all mutagens are genotoxic, but some geno ...

stress.

References

External links

* * DNA {{genetics-stub