Peptidoglycan (PG) is an essential constituent of the bacterial cell wall. During cell division, the machinery responsible for PG synthesis localizes mid-cell, at the septum, under the control of a multiprotein complex called the divisome. In Escherichia coli, septal PG synthesis and cell constriction rely on the accumulation of FtsN at the division site. Interestingly, a short sequence of FtsN (Leu75–Gln93, known as EFtsN) was shown to be essential and sufficient for its functioning in vivo, but what exactly this sequence is doing remained unknown. Here, we show that EFtsN binds specifically to the major PG synthase PBP1b and is sufficient to stimulate its biosynthetic glycosyltransferase (GTase) activity. We also report the crystal structure of PBP1b in complex with EFtsN, which demonstrates that EFtsN binds at the junction between the GTase and UB2H domains of PBP1b. Interestingly, mutations to two residues (R141A/R397A) within the EFtsN-binding pocket reduced the activation of PBP1b by FtsN but not by the lipoprotein LpoB. This mutant was unable to rescue the ΔponB-ponAts strain, which lacks PBP1b and has a thermosensitive PBP1a, at nonpermissive temperature and induced a mild cell-chaining phenotype and cell lysis. Altogether, the results show that EFtsN interacts with PBP1b and that this interaction plays a role in the activation of its GTase activity by FtsN, which may contribute to the overall septal PG synthesis and regulation during cell division.

In a network containing multiple nodes, the need for synchronization between the various nodes is not just instrumental but also a complicated and highly complex process. This process becomes even more tricky if we synchronize the clocks between the Manager and the Peripheral. As we know, in a real-time network, some of the nodes would behave like Managers while some would be a Peripheral. If we must make the communication process smooth, then the local clocks of these nodes must be synchronized. 

The problem with this synchronization is that we have the clock running in the Manager as well. If we send the value of the Manager clock to the Peripheral, the synchronization doesn’t happen as we have a propagation delay of the messages, along with the propagation delay of the electronic circuits of Manager and the Peripheral.  

The cherry on the cake is that these electronic circuit propagation delays are not random and remain constant, so we can add a time offset to it to match the clock. To tackle this challenge, IEEE has come up with a protocol named “Precision Timing Protocol.” 

Operation of PTP: 

To synchronize the clocks, a Sync message is sent by the Manager to the Peripheral, which then timestamps the receiving time of the same. Following this, a ‘Follow up’ message is issued by the Manager stating the timestamp at which the Sync message was sent. 

The Peripheral then finds the difference between the two values and adds this to its current time. After this, the time difference between the Manager and the Peripheral narrows down to only the propagation delay of the messages.  

To overcome this, the Peripheral issues a ‘Delay Request’ to the Manager, and the Manager, in turn, issues a ‘Delay Response.’ Both these messages have the timestamp of when they were issued. The time at which they are received is then noted. Since two messages are sent, one from the Peripheral and the other from the Manager, there are two propagation delays. Then half of this value is our propagation delay. 

The Peripheral then adds this propagation delay to its clock, and hence the clock gets synchronized. 

Advantages of PTP: 

1. It provides accurate time stamping. 
2. It is a well-known clock synchronization protocol. 
3. It provides intensified security inside the premises. 
4. It provides the possibility of setting coordinated actions and synchronized communication. 

There are various versions of PTP that have been developed over time, namely PTPv1, PTPv2, PTPv2_1, and the latest PTP-AS. 

Cadence Verification IP for Ethernet is available to support the newer version of PTP, allowing simulation of the device for efficient IP, SoC, and system-level design verification. Semiconductor companies can start using it to fully verify their controller design and achieve functional verification closure on it within no time. 

After eluding scientists for nearly 80 years, the Clarion nightsnake (Hypsiglena ochrorhyncha unaocularus), a nocturnal reptilian species that was initially discovered in the first half […]

The post Lost species of nightsnake rediscovered in Mexico appeared first on Smithsonian Insider.

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Spectrum reached an agreement to carry SportsNet LA, the Dodgers' television home, on AT&T video platforms, including DirecTV, AT&T TV and U-Verse TV.

Imports (Bop) -Natural Gas, Natural Gas Liquids&Related Products in Canada increased to 240.70 CAD Million in March from 213.70 CAD Million in February of 2020. Imports (Bop) -Natural Gas, Natural Gas Liquids&Re in Canada averaged 200.63 CAD Million from 1988 until 2020, reaching an all time high of 839.50 CAD Million in April of 2014 and a record low of 0.90 CAD Million in February of 1988. This page includes a chart with historical data for Canada Imports of (bop) -natural Gas, Natural Gas Liquid.

Australia. Parliament. Senate. Community Affairs References Committee

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