TY - JOUR
T1 - Cloning and sequencing of the gene for a 120-kDa immunodominant protein of Ehrlichia chaffeensis
AU - Yu, Xue Jie
AU - Crocquet-Valdes, Patricia
AU - Walker, David H.
N1 - Funding Information:
The authors would like to thank Josie Ramirez and Kay Kantowski for their assistance in the preparation of the manuscript. This study was supported by a research grant from the National Institute of Allergy and Infectious Diseases (AI31431).
PY - 1997/1/15
Y1 - 1997/1/15
N2 - Ehrlichia chaffeensis is the tick-borne, obligately intracellular bacterium that causes human monocytic ehrlichiosis. A 120-kDa protein is one of the immunodominant proteins of E. chaffeensis that stimulates production of specific antibodies in infected humans. A genomic library of E. chaffeensis was constructed in a λZAP II phage vector, and a clone expressing the 120-kDa protein of E. chaffeensis was identified using canine anti-E. chaffeensis serum. DNA sequence analysis of the cloned 120-kDa protein gene of E. chaffeensis identified a 1884-bp open reading frame with an ehrlichial promoter. Five identical 240-bp tandem repeat units were identified in the 120-kDa protein gene of E. chaffeensis, comprising 60% of the entire gene. Aside from the first repeat unit, all the other repeat units are identical. In the first repeat unit there are four nucleotides that are different from the other repeats. Hydropathy analysis of the deduced amino-acid sequence demonstrated that the repeat domain contains highly hydrophilic segments. The 120-kDa protein should be evaluated for a role in stimulating protective immunity.
AB - Ehrlichia chaffeensis is the tick-borne, obligately intracellular bacterium that causes human monocytic ehrlichiosis. A 120-kDa protein is one of the immunodominant proteins of E. chaffeensis that stimulates production of specific antibodies in infected humans. A genomic library of E. chaffeensis was constructed in a λZAP II phage vector, and a clone expressing the 120-kDa protein of E. chaffeensis was identified using canine anti-E. chaffeensis serum. DNA sequence analysis of the cloned 120-kDa protein gene of E. chaffeensis identified a 1884-bp open reading frame with an ehrlichial promoter. Five identical 240-bp tandem repeat units were identified in the 120-kDa protein gene of E. chaffeensis, comprising 60% of the entire gene. Aside from the first repeat unit, all the other repeat units are identical. In the first repeat unit there are four nucleotides that are different from the other repeats. Hydropathy analysis of the deduced amino-acid sequence demonstrated that the repeat domain contains highly hydrophilic segments. The 120-kDa protein should be evaluated for a role in stimulating protective immunity.
KW - DNA repeat units
KW - Ehrlichiosis
KW - Obligate intracellular bacterium
UR - http://www.scopus.com/inward/record.url?scp=0031033764&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0031033764&partnerID=8YFLogxK
U2 - 10.1016/S0378-1119(96)00586-0
DO - 10.1016/S0378-1119(96)00586-0
M3 - Article
C2 - 9031621
AN - SCOPUS:0031033764
SN - 0378-1119
VL - 184
SP - 149
EP - 154
JO - Gene
JF - Gene
IS - 2
ER -