학술논문
In vivo crystal formation in Escherichia coli of an over-expressed soluble form of penicillin-binding protein 5
Document Type
Article
Source
FEMS Microbiology Letters; December 1992, Vol. 99 Issue: 2-3 p117-117, 1p
Subject
Language
ISSN
03781097; 15746968
Abstract
Accumulation of either native membrane-bound or soluble variants of PBP5 over-expressed in teh cytoplasm was investigated by electron microscopy of ultra-thin sections. One of the soluble forms of PBP5 (PBP5s353) formed well-ordered crystals inside the cells. Cells sectioned perpendicular to their long axis showed a diamond-shaped cyrstal whereas cells cut parallel to their long axis contained a long, narrow crystal. In both sectioning directions an ordered ultra-structure was visible as shown by optical diffraction. Computer processing was used to enhance the crystal images. From this the unit cell parameters were calculated as a= 7.6 nm, b= 4 nm, c= 4.2 nm, γ= 75°. The calculated unit-cell volume of 120 nm3 is large enough to contain one protein molecule.