50S ribosomal subunit protein L32; Protein involved in structural constituent of ribosome and translation.

50S ribosomal subunit protein L19; This protein is located at the 30S-50S ribosomal subunit interface. In the 70S ribosome it has been modeled to make two contacts with the 16S rRNA of the 30S subunit forming part of bridges B6 and B8. In the 3.5 A resolved structures L14 and L19 interact and together make contact with the 16S rRNA. The protein conformation is quite different between the 50S and 70S structures, which may be necessary for translocation.

(p)ppGpp synthetase I/GTP pyrophosphokinase; In eubacteria ppGpp (guanosine 3'-diphosphate 5-' diphosphate) is a mediator of the stringent response which coordinates a variety of cellular activities in response to changes in nutritional abundance. This enzyme catalyzes the formation of pppGpp which is then hydrolyzed to form ppGpp. The second messengers ppGpp and c-di-GMP together control biofilm formation in response to translational stress; ppGpp represses biofilm formation while c-di-GMP induces it. ppGpp activates transcription of CsrA-antagonistic small RNAs CsrB and CsrC, which d [...]

50S ribosomal subunit protein L21; This protein binds to 23S rRNA in the presence of protein L20.

30S ribosomal subunit protein S9; The C-terminal tail plays a role in the affinity of the 30S P site for different tRNAs. Mutations that decrease this affinity are suppressed in the 70S ribosome.

50S ribosomal subunit protein L13; This protein is one of the early assembly proteins of the 50S ribosomal subunit, although it is not seen to bind rRNA by itself. It is important during the early stages of 50S assembly.

50S ribosomal subunit protein L17; Requires L15 for assembly into the 50S subunit.

RNA polymerase, alpha subunit; DNA-dependent RNA polymerase (RNAP) catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. This subunit plays an important role in subunit assembly since its dimerization is the first step in the sequential assembly of subunits to form the holoenzyme.

30S ribosomal subunit protein S4; One of two assembly initiator proteins for the 30S subunit, it binds directly to 16S rRNA where it nucleates assembly of the body of the 30S subunit. Plays a role in mRNA unwinding by the ribosome, possibly by forming part of a processivity clamp. Also functions as a rho-dependent antiterminator of rRNA transcription, increasing the synthesis of rRNA under conditions of excess protein, allowing a more rapid return to homeostasis. Binds directly to RNA polymerase; Belongs to the universal ribosomal protein uS4 family.