597 sam's club stores are in the usa.
597 sam's club stores are in the usa.
how many sam's club stores are in the usa?
597
Na
Na
the sam riboswitch (also known as the s-box leader and the sam-i riboswitch) is found upstream of a number of genes which code for proteins involved in methionine or cysteine biosynthesis in gram-positive bacteria. two sam riboswitches in "bacillus subtilis" that were experimentally studied act at the level of transcription termination control. the predicted secondary structure consists of a complex stem-loop region followed by a single stem-loop terminator region. an alternative and mutually exclusive form involves bases in the 3' segment of helix 1 with those in the 5' region of helix 5 to form a structure termed the anti-terminator form. when sam is unbound, the anti-terminator sequence sequesters the terminator sequence so the terminator is unable to form, allowing the polymerase read-through the downstream gene. when the sam is bound to the aptamer, the anti-terminator is sequestered by an anti-anti-terminator; the terminator forms and terminates the transcription. however, many sam riboswitches are likely to regulate gene expression at the level of translation.
sam riboswitch (s-box leader)