Lin C, Stahl D A
Department of Veterinary Pathobiology, University of Illinois at Urbana-Champaign 61801, USA.
J Bacteriol. 1995 May;177(9):2543-9. doi: 10.1128/jb.177.9.2543-2549.1995.
An RNA probe complementary to the endoglucanase 3 gene (cel-3) of Fibrobacter succinogenes S85 hybridized to chromosomal DNAs from isolates representing the genetic diversity of the genus. The probe was subsequently used to identify putative cel-3-containing clones from genomic libraries of representative Fibrobacter isolates. Comparative sequence analyses of the cloned cel-3 genes confirmed that cel-3 is conserved among Fibrobacter isolates and that the ancestral cel-3 gene appears to have coevolved with the genus, since the same genealogy was inferred from sequence comparisons of 16S rRNAs and cel-3 genes. Hybridization comparisons using a xylanase gene probe suggested similar conservation of this gene. Together the data indicate that the cellulolytic apparatus is conserved among Fibrobacter isolates and that comparative analyses of homologous elements of the apparatus from different members, in relationship to the now established phylogeny of the genus, could serve to better define the enzymatic basis of fiber digestion in this genus.
一种与琥珀酸纤维杆菌S85的内切葡聚糖酶3基因（cel-3）互补的RNA探针，与代表该属遗传多样性的分离株的染色体DNA杂交。随后，该探针被用于从代表性纤维杆菌分离株的基因组文库中鉴定假定含有cel-3的克隆。对克隆的cel-3基因进行的比较序列分析证实，cel-3在纤维杆菌分离株中是保守的，并且由于从16S rRNA和cel-3基因的序列比较中推断出相同的谱系，祖先cel-3基因似乎与该属共同进化。使用木聚糖酶基因探针进行的杂交比较表明该基因具有类似的保守性。这些数据共同表明，纤维杆菌分离株中的纤维素分解装置是保守的，并且根据该属现已确定的系统发育，对来自不同成员的该装置的同源元件进行比较分析，有助于更好地确定该属中纤维消化的酶学基础。
