Table 2

Large-subunit proteins from Haloarcula marismortui. The top block of proteins include all those known to have eubacterial homologs of the same name. The second block lists proteins found in the H. marismortui large ribosomal subunit that have only eukaryotic homologs (19). Their names are all followed by the letter “e” to distinguish them from eubacterial proteins that would otherwise have the same name. The third block are large-subunit proteins for which no H. marismortuisequence yet exists. They are identified by sequence homology with standard L names. 1The structures of all or part of homologs of the following proteins were previously determined: L1 (28), L2 (43), L4 (44), L6 (58), L11 (21,22, 59), L12 (60), L14 (61), L22 (62), and L30 (63). All other structures, except L10, have been newly determined in this study. 2Rat homolog. Rat equivalents to H. marismortui protein are from (26). 3Sequence chain length.4Conformation: glb, globular; ext, extension.5The protein interactions with the six domains of 23S rRNA, 5S rRNA, and other proteins are specified. (+) Implies that the interaction is substantial; (±) implies a weak, tangential interaction. Protein names in parentheses implies that the interactions are weak; otherwise, the interaction is substantial.

Name1Hmlg2Lgth3Conf4Interactions5Proteins
IIIIIIIVVVI5S
L1* ?211glb.++None
L2 RL8239glb+ext++++(L37ae)
L3RL3337glb+ext±+++L14, L24e, (L13)
L4 RL4246glb+ext++±(L18e), (L24), (L37e)
L5RL11176glb++L18
L6RL9177glb±±+(L13)
L10* RP0348glb?+L12
L11* RL12161glb+None
L12* RP1/2115glbL10
L13RL13a145glb+±±(L3), (L6)
L14RL23132glb+++L3, L24e
L15RL27a164glb+ext++++(L18e), (L32e)
L18RL5186glb+ext±++L5, L21e
L19RL19148glb+ext+++±None
L22RL17154glb+ext+±++++None
L23RL23a84glb±+L29, (L39e)
L24RL26119glb+ext+(L4)
L29RL3570glb+L23
L30RL7154glb++None
L18eRL18115glb+(L4), (L15)
L21eRL2195glb+++±L18
L24eRL2466glb±+L3, L14
L31eRL3191glb+++None
L32eRL32240glb±+(L15)
L37eRL3756glb+ext+++±(L4)
L39eRL3949ext++(L23)
L44eRL36a92glb+ext+±+(L15e)
L7aeRL7a110glb±L15e
L10eRL10163glb+++±None
L15eRL15184glb+ext+±±±+(L44e), L7ae
L37aeRL37a72glb+ext+++L2
  • * All entries so designated describe proteins that are not fully represented in the electron density maps described here. The summary information provided is derived from literature sources and is included here for completeness only.

  • The structure available for this protein in isolation does not include the extension(s) reported here.