当前位置： SCI文献检索 > PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA期刊下所有文献 > In vitro sulfotransferase activity of Rhizobium meliloti NodH protein: lipochitooligosaccharide nodulation signals are sulfated after synthesis of the core structure.

In vitro sulfotransferase activity of Rhizobium meliloti NodH protein: lipochitooligosaccharide nodulation signals are sulfated after synthesis of the core structure.

Abstract：

:The Rhizobium common nod gene products NodABC are involved in the synthesis of the core lipochitooligosaccharide (Nod factor) structure, whereas the products of the host-specific nod genes are necessary for diverse structural modifications, which vary in different Rhizobium species. The sulfate group attached to the Rhizobium meliloti Nod signal is necessary for activity on the host plant alfalfa, while its absence renders the Nod factor active on the non-host plant vetch. This substituent is therefore a major determinant of host specificity. The exact biosynthetic pathway of Nod factors has not been fully elucidated. In particular, it is not known why some chemical modifications are introduced with high fidelity whereas others are inaccurate, giving rise to a family of different Nod factor structures produced by a single Rhizobium strain. Using protein extracts and partially purified recombinant NodH protein obtained from Escherichia coli expressing the R. meliloti nodH gene, we demonstrate here NodH-dependent in vitro sulfotransferase activity. Kinetic analyses with Nod factors, chitooligosaccharides, and their deacetylated derivatives revealed that Nod factors are the preferred substrate for the sulfate transfer. Moreover, the tetrameric Nod factor, NodRm-IV, was a better substrate than the trimer, NodRm-III, or the pentamer, NodRm-V. These data suggest that the core lipochitooligosaccharide structure must be synthesized prior to its host-specific modification with a sulfate group. Since in R. meliloti tetrameric Nod factors are the most abundant and the most active ones, high affinity of NodH for the appropriate tetrameric substrate guarantees its modification and thus contributes to the fidelity of host-specific behavior.

journal_name

Proc Natl Acad Sci U S A

journal_title

Proceedings of the National Academy of Sciences of the United States of America

authors

Schultze M,Staehelin C,Röhrig H,John M,Schmidt J,Kondorosi E,Schell J,Kondorosi A

doi

10.1073/pnas.92.7.2706

subject

Has Abstract

pub_date

1995-03-28 00:00:00

pages

2706-9

issue

eissn

0027-8424

issn

1091-6490

journal_volume

pub_type

杂志文章

在线工具

In vitro sulfotransferase activity of Rhizobium meliloti NodH protein: lipochitooligosaccharide nodulation signals are sulfated after synthesis of the core structure.