Journal: Journal of Bacteriology
Article Title: Differential Regulation of the PanA and PanB Proteasome-Activating Nucleotidase and 20S Proteasomal Proteins of the Haloarchaeon Haloferax volcanii †
Figure Lengend Snippet: Amino acid sequence alignment of H. volcanii PanA and PanB. Identical residues are shaded in black. Functionally conserved and semiconserved amino acid residues are shaded in grey. Dashes indicate gaps introduced in the protein sequence alignment. Boxed residues were predicted with a > 90% probability to form a coiled-coil conformation (see Materials and Methods). Consensus sequences of the Walker A and B boxes of the P-loop nucleotidase core are indicated below the alignment as GX 2 GXGKT and DEXD, respectively (where X is any amino acid residue). The AAA ATPase second region of homology or SHR motif [(T/S)-(N/S)-X 5 -DXA-X 2 -R-X 2 -RX-(D/E)] is also indicated. The N-terminal sequences of the PanA-His and PanA Δ1-40 -His antigens were identical to residues 2 to 14 and 41 to 51 of the deduced primary sequence, respectively. MALDI-TOF Q-STAR detected the mass spectra of 11 tryptic fragments of the PanB-His antigen, which encompassed 36% of the primary amino acid sequence. The masses (in daltons) and corresponding residue numbers of PanB-His were as follows: 716.3148, 30 to 34; 749.3711, 35 to 40; 1,004.5522, 330 to 337; 1,264.6408, 205 to 261; 1,307.7720, 317 to 328; 1,490.6807, 379 to 392; 1,548.7975, 301 to 313; 1,836.7691, 275 to 289; 2,180.0845, 118 to 137; 2,408.1564, 4 to 24; 2,739.3637, 138 to 162.
Article Snippet: Prior to antibody preparation, the N-terminal sequences of PanAΔ1-40 -His and PanA-His were determined by Edman degradation, and the mass spectra of the tryptic fragments of PanB-His were determined by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry (Applied Biosystems QSTAR XL hybrid LC/MS/MS; University of Florida ICBR Protein Chemistry Core).