Mitochondria and chloroplasts are two distinct organelles essential for plant viability. They evolved from prokaryotic endosymbionts and share a common ancestor with extant Gram-negative bacteria (Gray et al., 1999; Gould et al., 2008). Successful conversion of the free-living prokaryotes to the cytoplasmic organelles via endosymbiosis required conservation and adaptation of the outer membranes...

Recently, Y.-Y. Huang and C.-C. Hong [15, 16], T.-J. Huang and Y.-Y. Huang [14], and Y.-Y. Huang et al. [17] obtained a few fixed point theorems for left reversible and nearcommutative semigroups of contractive self-mappings in compact and complete metric spaces, respectively. These results subsume some theorems in Boyd and Wong [1], Edelstein [3], and Liu [20]. In this paper, motivated by the ...

A mutant strain of Mycobacterium smegmatis defective in the biosynthesis of mycolic acids was recently isolated (Liu, J., and Nikaido, H. (1999) Proc. Natl. Acad. Sci. U. S. A. 96, 4011-4016). This mutant failed to synthesize full-length mycolic acids and accumulated a series of long chain beta-hydroxymeromycolates. In this work, we provide a detailed characterization of the localization of mer...

The assembly of outer membrane proteins of Escherichia coli was examined using the OmpF porin as a model. Since this protein is made as a precursor, which is processed to a protein of Mr 37,000 before being assembled into trimers in the outer membrane, we synthesized a modified OmpF, which lacked 16 out of 22 amino acid residues from its signal sequence, in a coupled transcription-translation s...

Perfect phylogeny is one of the fundamental models for studying evolution. We investigate the following variant of the problem: The input is an n ×m species-characters matrix. The characters are binary and directed, i.e., a species can only gain characters. The difference from standard perfect phylogeny is that for some species the state of some characters is unknown. The question is whether on...

The crystal structure of the MJ0796 ATP-binding cassette, a member of the o228/LolD transporter family, has been determined at 2.7-A resolution with MgADP bound at its active site. Comparing this structure with that of the ATP-bound form of the HisP ATP-binding cassette (Hung, L. W., Wang, I. X., Nikaido, K., Liu, P. Q., Ames, G. F., and Kim, S. H. (1998) Nature 396, 703-707) shows a 5-A withdr...